refactor: extract ChatOverlayLayer — real component decomposition, Commit G

The first true decomposition of the 4105-line god-object, not another partial
shuffle. MainViewModel.Chat.cs 194 -> 44 lines of thin delegation; all chat
behavior now lives in a self-contained Services/ChatOverlayLayer.cs (199):

- Owns the message buffer (Messages), ChatBoxRenderer, fade + mock-preview
  timers, per-source preview renders, and the live-output RenderFrame path.
- The VM keeps only the binding surface: ChatMessages delegates to
  _chatLayer.Messages (so XAML ItemsSource + LeftPanel CollectionChanged hold),
  CanAddYouTubeChat / ShowChatInactiveMessage stay computed on the VM
  (OnPropertyChanged raised from VM setters + XAML-bound), and thin forwards.
- Scenes handed in as args (no Func seam), so the layer owns no scene graph.

An AI reading ChatOverlayLayer.cs now sees the entire chat feature in one
self-contained unit. Zero behavior change; build 0 warnings; 246 pass, only the
2 known failures. Docs: ViewModels/index.md tracker updated in same commit.

Controls/LeftPanel.xaml

@@ -0,0 +1,499 @@
+<UserControl x:Class="ytLive.Controls.LeftPanel"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:Helpers="clr-namespace:ytLive.Helpers"
+             xmlns:models="clr-namespace:ytLive.Models">
+    <Border Background="#16213e" CornerRadius="6" Padding="12">
+                <Grid>
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="*"/>
+                    </Grid.RowDefinitions>
+
+                    <!-- Edit mode (offline): layers + properties -->
+                    <Grid Grid.Row="0" Visibility="{Binding IsEditMode, Converter={StaticResource BoolToVis}}">
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="*"/>
+                        </Grid.RowDefinitions>
+
+                        <!-- LAYERS header + Add button -->
+                        <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="0,8,0,0">
+                            <TextBlock Text="LAYERS" Style="{StaticResource SectionHeader}" VerticalAlignment="Center"/>
+                            <Button ToolTip="Add Layer" Style="{StaticResource IconButton}" Margin="4,-4,0,0"
+                                Click="AddSourceButton_Click">
+                            <Button.ContextMenu>
+                                <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
+                                    <MenuItem Header="Webcam" Command="{Binding AddWebcamCommand}"
+                                              IsEnabled="{Binding CanAddWebcam}"
+                                              ToolTip="One webcam at a time — it's already in your stream"/>
+                                    <MenuItem Header="Image" Command="{Binding AddImageCommand}"/>
+                                    <MenuItem Header="Text" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.TextOverlay}"/>
+                                    <MenuItem Header="Countdown" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.Countdown}"
+                                              Visibility="{Binding IsCountdownAvailable, Converter={StaticResource BoolToVis}}"
+                                              ToolTip="Timer overlay — Starting and BRB screens only"/>
+                                    <MenuItem Header="Web Resource" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.WebSource}"
+                                              ToolTip="Embedded web page — set URI in Properties panel"/>
+                                    <MenuItem Header="YouTube Chat" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.ChatBox}"
+                                              IsEnabled="{Binding CanAddYouTubeChat}"
+                                              ToolTip="One chat layer at a time — it's already in your stream"/>
+                                </ContextMenu>
+                            </Button.ContextMenu>
+                            <Path Data="M12,4 L12,20 M4,12 L20,12" Stroke="#e94560" StrokeThickness="2"
+                                  Width="14" Height="14" Stretch="Uniform"/>
+                        </Button>
+                    </StackPanel>
+
+                    <Helpers:FocusPreservingListBox x:Name="SourceList" Grid.Row="1" Background="Transparent" BorderThickness="0"
+                             ItemsSource="{Binding StagedScene.Elements}"
+                             SelectedItem="{Binding SelectedElement, Mode=TwoWay}"
+                             PreviewMouseLeftButtonDown="List_PreviewMouseLeftButtonDown"
+                             PreviewMouseMove="List_PreviewMouseMove"
+                             PreviewMouseLeftButtonUp="List_PreviewMouseLeftButtonUp"
+                             Foreground="#e0e0e0" FontSize="13">
+                        <Helpers:FocusPreservingListBox.ItemContainerStyle>
+                            <Style TargetType="ListBoxItem" BasedOn="{StaticResource YtListBoxItem}">
+                                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+                                <Style.Triggers>
+                                    <DataTrigger Binding="{Binding IsVisible}" Value="False">
+                                        <Setter Property="Opacity" Value="0.45"/>
+                                    </DataTrigger>
+                                </Style.Triggers>
+                            </Style>
+                        </Helpers:FocusPreservingListBox.ItemContainerStyle>
+                        <ListBox.ItemTemplate>
+                            <DataTemplate>
+                                <Grid Margin="0,2"
+                                      Tag="{Binding DataContext.CanChangeBackground, RelativeSource={RelativeSource AncestorType=Window}}">
+                                    <Grid.ColumnDefinitions>
+                                        <ColumnDefinition Width="*"/>
+                                        <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="Auto"/>
+                                        <ColumnDefinition Width="Auto"/>
+                                    </Grid.ColumnDefinitions>
+
+                                    <Grid.ContextMenu>
+                                        <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
+                                            <MenuItem Header="Change Capture…" Click="BackgroundMenu_ChangeCapture">
+                                                <MenuItem.Visibility>
+                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
+                                                        <Binding Path="IsBackground"/>
+                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
+                                                    </MultiBinding>
+                                                </MenuItem.Visibility>
+                                            </MenuItem>
+                                            <MenuItem Header="Refresh Capture" Click="BackgroundMenu_RefreshCapture">
+                                                <MenuItem.Visibility>
+                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
+                                                        <Binding Path="IsBackground"/>
+                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
+                                                    </MultiBinding>
+                                                </MenuItem.Visibility>
+                                            </MenuItem>
+                                            <Separator>
+                                                <Separator.Visibility>
+                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
+                                                        <Binding Path="IsBackground"/>
+                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
+                                                    </MultiBinding>
+                                                </Separator.Visibility>
+                                            </Separator>
+                                            <MenuItem Header="Remove Layer" Click="SourceMenu_Remove"
+                                                      Visibility="{Binding IsBackground, Converter={StaticResource InverseBoolToVis}}"/>
+                                        </ContextMenu>
+                                    </Grid.ContextMenu>
+
+                                    <TextBlock Grid.Column="0" Text="{Binding Name}" VerticalAlignment="Center"
+                                               Padding="4,2" TextTrimming="CharacterEllipsis">
+                                        <TextBlock.Style>
+                                            <Style TargetType="TextBlock">
+                                                <Setter Property="Visibility" Value="Visible"/>
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
+                                                        <Setter Property="Visibility" Value="Collapsed"/>
+                                                    </DataTrigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </TextBlock.Style>
+                                    </TextBlock>
+
+                                    <TextBox Grid.Column="0" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="0"
+                                             Padding="4,2" VerticalContentAlignment="Center"
+                                             IsVisibleChanged="SourceNameBox_IsVisibleChanged"
+                                             KeyDown="SourceNameBox_KeyDown" LostFocus="SourceNameBox_LostFocus">
+                                        <TextBox.Style>
+                                            <Style TargetType="TextBox">
+                                                <Setter Property="Visibility" Value="Collapsed"/>
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
+                                                        <Setter Property="Visibility" Value="Visible"/>
+                                                    </DataTrigger>
+                                                </Style.Triggers>
+                                            </Style>
+                                        </TextBox.Style>
+                                    </TextBox>
+
+                                    <Button Grid.Column="1" ToolTip="Edit Layer Name"
+                                            Command="{Binding DataContext.EditElementCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
+                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}">
+                                        <Path Data="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z"
+                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
+                                    </Button>
+
+                                    <Button Grid.Column="2" Style="{StaticResource EyeButton}"
+                                            Command="{Binding DataContext.ToggleElementVisibilityCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
+                                            CommandParameter="{Binding}">
+                                        <Path Style="{StaticResource EyeIconStyle}" Fill="#d0d0d0"
+                                              Width="13" Height="13" Stretch="Uniform"/>
+                                    </Button>
+
+                                    <Button Grid.Column="3" ToolTip="Remove Layer"
+                                            Command="{Binding DataContext.RemoveSourceCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
+                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}"
+                                            Visibility="{Binding IsBackground, Converter={StaticResource HiddenBoolToVis}}">
+                                        <Path Data="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2V7H6v12zM19,4h-3.5l-1,-1h-5l-1,1H5v2h14V4z"
+                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
+                                    </Button>
+                                </Grid>
+                            </DataTemplate>
+                        </ListBox.ItemTemplate>
+                    </Helpers:FocusPreservingListBox>
+
+                            <TextBlock Grid.Row="2" Text="No layers yet" Foreground="#555" FontSize="12"
+                               HorizontalAlignment="Center" VerticalAlignment="Center"
+                               Visibility="{Binding ShowSourcesEmptyHint, Converter={StaticResource BoolToVis}}"/>
+
+                    <!-- ELEMENTS panel: per-element config beneath Sources.
+                         Collapses entirely when no element is selected. -->
+                    <Rectangle Grid.Row="3" Height="1" Fill="#2c3a5c" Margin="0,10,0,2"
+                               Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}"/>
+                    <StackPanel Grid.Row="4" Orientation="Horizontal" Margin="0,8,0,0"
+                                Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}">
+                        <TextBlock Text="PROPERTIES" Style="{StaticResource SectionHeader}" VerticalAlignment="Center"/>
+                    </StackPanel>
+                    <ScrollViewer x:Name="ElementsScrollViewer" Grid.Row="5" VerticalScrollBarVisibility="Auto" Background="Transparent"
+                                  Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}">
+                        <StackPanel x:Name="ElementsPanel" Margin="0,4,0,0">
+                            <!-- Opacity + mirror/shape (draggable elements: image, webcam) -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsDraggable, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <StackPanel Visibility="{Binding SelectedElement.IsChatBox, Converter={StaticResource InverseBoolToVis}}">
+                                    <TextBlock Text="Opacity" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
+                                    <DockPanel Margin="0,0,0,6">
+                                        <TextBlock x:Name="OpacityValueText" Text="100%" Foreground="#a0a0b0" FontSize="11"
+                                                   DockPanel.Dock="Right" VerticalAlignment="Center" Margin="8,0,0,0" Width="32"/>
+                                        <Slider x:Name="OpacitySlider" Width="120" Minimum="0" Maximum="1"
+                                                Value="{Binding SelectedElement.Opacity, Mode=TwoWay}"
+                                                ValueChanged="OpacitySlider_ValueChanged" VerticalAlignment="Center"/>
+                                    </DockPanel>
+                                </StackPanel>
+                                <StackPanel Orientation="Horizontal" Margin="0,0,0,4"
+                                            Visibility="{Binding IsWebcamSelected, Converter={StaticResource BoolToVis}}">
+                                    <Button Content="{Binding SelectedElement.MirrorButtonText}"
+                                            Style="{StaticResource YtButtonSecondary}" Padding="10,4"
+                                            Click="MirrorButton_Click"/>
+                                    <Button Content="{Binding SelectedElement.ShapeButtonText}"
+                                            Style="{StaticResource YtButtonSecondary}" Padding="10,4"
+                                            Margin="8,0,0,0" Click="ShapeButton_Click"/>
+                                </StackPanel>
+                                <TextBlock Text="Drag to move · drag the corner dot to resize"
+                                           Foreground="#a0a0b0" FontSize="10" Margin="0,2,0,0"/>
+                            </StackPanel>
+
+                            <!-- Webcam border config -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsWebcam, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <TextBlock Text="Border Color" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
+                                <DockPanel Margin="0,0,0,6">
+                                    <Button DockPanel.Dock="Right" Content="..." Width="24" Height="24"
+                                            Click="WebcamBorderColorPicker_Click" Margin="4,0,0,0"
+                                            ToolTip="Pick color"/>
+                                    <TextBox Text="{Binding SelectedElement.BorderColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"
+                                             MaxLength="7" ToolTip="#RRGGBB"/>
+                                </DockPanel>
+                                <TextBlock Text="Border Thickness" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
+                                <DockPanel Margin="0,0,0,6">
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" Margin="4,0,0,0"
+                                            Click="WebcamBorderAccept_Click">
+                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" ToolTip="Revert"
+                                            Click="WebcamBorderRevert_Click" Margin="4,0,0,0">
+                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <Slider DockPanel.Dock="Left" Width="120" Minimum="0" Maximum="10"
+                                            Value="{Binding SelectedElement.BorderWidth, Mode=TwoWay}"
+                                            VerticalAlignment="Center" TickFrequency="1" IsSnapToTickEnabled="True"/>
+                                    <TextBlock Text="{Binding SelectedElement.BorderWidth}" Foreground="#a0a0b0" FontSize="11"
+                                               VerticalAlignment="Center" Margin="8,0,0,0" Width="20"/>
+                                </DockPanel>
+                            </StackPanel>
+
+                            <!-- Countdown config -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsCountdown, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <TextBlock Text="Timer (minutes)" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
+                                <DockPanel Margin="0,0,0,6">
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" Margin="4,0,0,0"
+                                            Click="CountdownAccept_Click">
+                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" ToolTip="Revert"
+                                            Click="CountdownRevert_Click" Margin="4,0,0,0">
+                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <Slider DockPanel.Dock="Left" Width="120" Minimum="1" Maximum="60"
+                                            Value="{Binding SelectedElement.TimerMinutes, Mode=TwoWay}"
+                                            VerticalAlignment="Center" TickFrequency="1" IsSnapToTickEnabled="True"/>
+                                    <TextBlock Text="{Binding SelectedElement.TimerMinutes}" Foreground="#a0a0b0" FontSize="11"
+                                               VerticalAlignment="Center" Margin="8,0,0,0" Width="20"/>
+                                </DockPanel>
+                            </StackPanel>
+
+                            <!-- Web source config -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsWebSource, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <TextBlock Text="Geometry" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold" Margin="0,0,0,4"/>
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="X" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="16"/>
+                                    <TextBox Text="{Binding SelectedElement.X, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
+                                    <TextBlock DockPanel.Dock="Left" Text="  Y" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="20" Margin="8,0,0,0"/>
+                                    <TextBox Text="{Binding SelectedElement.Y, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
+                                </DockPanel>
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="W" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="16"/>
+                                    <TextBox Text="{Binding SelectedElement.Width, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
+                                    <TextBlock DockPanel.Dock="Left" Text="  H" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="20" Margin="8,0,0,0"/>
+                                    <TextBox Text="{Binding SelectedElement.Height, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
+                                </DockPanel>
+                                <TextBlock Text="URI" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
+                                <DockPanel>
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" Margin="4,0,0,0" IsTabStop="False"
+                                            Click="WebAccept_Click">
+                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
+                                            Width="22" Height="22" ToolTip="Revert" IsTabStop="False"
+                                            Click="WebRevert_Click" Margin="4,0,0,0">
+                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
+                                              Width="14" Height="14" Stretch="Uniform"/>
+                                    </Button>
+                                    <TextBox Text="{Binding SelectedElement.WebUri, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"
+                                             ToolTip="https://example.com"/>
+                                </DockPanel>
+                            </StackPanel>
+
+                            <!-- Chat box config -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsChatBox, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <TextBlock Text="Chat Overlay" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold" Margin="0,0,0,6"/>
+
+                                <!-- Font Size -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Font Size" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider x:Name="ChatFontSizeSlider" Width="120" Minimum="8" Maximum="72" TickFrequency="2" IsSnapToTickEnabled="True"
+                                            Value="{Binding SelectedElement.ChatFontSize, Mode=TwoWay}"
+                                            VerticalAlignment="Center"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatFontSize, StringFormat={}{0:0}}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
+                                </DockPanel>
+
+                                <!-- Font Family -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Font" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <ComboBox SelectedValue="{Binding SelectedElement.ChatFontFamily, Mode=TwoWay}"
+                                              SelectedValuePath="Content"
+                                              Background="#0f3460" Foreground="#e0e0e0" FontSize="11"
+                                              Width="140" VerticalAlignment="Center">
+                                        <ComboBoxItem Content="Segoe UI"/>
+                                        <ComboBoxItem Content="Arial"/>
+                                        <ComboBoxItem Content="Consolas"/>
+                                        <ComboBoxItem Content="Courier New"/>
+                                        <ComboBoxItem Content="Comic Sans MS"/>
+                                        <ComboBoxItem Content="Mouse Memoirs"/>
+                                    </ComboBox>
+                                </DockPanel>
+
+                                <!-- Font Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Font Color" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatFontColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Member Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Member" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatMemberColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Super Chat Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Super Chat" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatSuperChatColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Max Messages -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Max Msgs" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider x:Name="ChatMaxMsgsSlider" Width="120" Minimum="1" Maximum="20" TickFrequency="1" IsSnapToTickEnabled="True"
+                                            Value="{Binding SelectedElement.ChatMaxMessages, Mode=TwoWay}"
+                                            VerticalAlignment="Center"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatMaxMessages}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
+                                </DockPanel>
+
+                                <!-- Background Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Background" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatBackgroundColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Background Opacity -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Bg Opacity" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider x:Name="ChatBgOpacitySlider" Width="120" Minimum="0" Maximum="1"
+                                            Value="{Binding SelectedElement.ChatBackgroundOpacity, Mode=TwoWay}"
+                                            VerticalAlignment="Center"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatBackgroundOpacity, StringFormat={}{0:0%}}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="32"/>
+                                </DockPanel>
+
+                                <!-- Fade After (seconds) -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Fade After" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider x:Name="ChatFadeSlider" Width="120" Minimum="0" Maximum="60" TickFrequency="5" IsSnapToTickEnabled="True"
+                                            Value="{Binding SelectedElement.ChatFadeSeconds, Mode=TwoWay}"
+                                            VerticalAlignment="Center"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatFadeSeconds, StringFormat='{}{0}s'}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="28"/>
+                                </DockPanel>
+
+                                <!-- Toggles -->
+                                <CheckBox Content="Show timestamps" Foreground="#a0a0b0" FontSize="11" Margin="0,4,0,2"
+                                          IsChecked="{Binding SelectedElement.ChatShowTimestamps, Mode=TwoWay}"/>
+                                <CheckBox Content="Show badges" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"
+                                          IsChecked="{Binding SelectedElement.ChatShowBadges, Mode=TwoWay}"/>
+                            </StackPanel>
+
+                            <!-- Background properties -->
+                            <StackPanel Margin="0,8,0,0"
+                                        Visibility="{Binding SelectedElement.IsBackground, Converter={StaticResource BoolToVis}}">
+                                <TextBlock Text="Background" Style="{StaticResource SubHeader}"/>
+                                <StackPanel Margin="4,0,0,0">
+                                    <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
+                                        <TextBlock Text="Use default background:" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center"/>
+                                        <ToggleButton Style="{StaticResource PillToggle}"
+                                                      IsChecked="{Binding SelectedElement.UseDefaultBackground, Mode=TwoWay}"
+                                                      Margin="8,0,0,0"/>
+                                    </StackPanel>
+                                    <Grid Margin="0,0,0,4"
+                                          Visibility="{Binding SelectedElement.UseDefaultBackground, Converter={StaticResource InverseBoolToVis}}">
+                                        <Grid.ColumnDefinitions>
+                                            <ColumnDefinition Width="*"/>
+                                            <ColumnDefinition Width="Auto"/>
+                                        </Grid.ColumnDefinitions>
+                                        <TextBox Grid.Column="0" Text="{Binding SelectedElement.CustomBackgroundPath, Mode=OneWay}"
+                                                  IsReadOnly="True" Background="#0f3460" Foreground="#a0a0b0"
+                                                  FontSize="11" VerticalAlignment="Center"/>
+                                        <Button Grid.Column="1" Content="Browse…" Command="{Binding BrowseBackgroundCommand}"
+                                                Style="{StaticResource YtButtonSecondary}" Margin="4,0,0,0" Padding="8,2"/>
+                                    </Grid>
+                                    <TextBlock Text="{Binding BackgroundSizeMismatchText}"
+                                               Foreground="#ef4444" FontSize="11" TextWrapping="Wrap"
+                                               Margin="0,4,0,0"
+                                               Visibility="{Binding BackgroundSizeMismatch, Converter={StaticResource BoolToVis}}"/>
+                                </StackPanel>
+                            </StackPanel>
+                        </StackPanel>
+                    </ScrollViewer>
+                </Grid>
+
+                <!-- Live mode: YouTube Live Chat (entire left panel replaced) -->
+                <Grid Grid.Row="0" Visibility="{Binding IsEditMode, Converter={StaticResource InverseBoolToVis}}">
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto"/>
+                        <RowDefinition Height="*"/>
+                    </Grid.RowDefinitions>
+
+                    <TextBlock Grid.Row="0" Text="LIVE CHAT" Style="{StaticResource SectionHeader}"/>
+
+                    <!-- Inactive overlay (shown when NOT live) -->
+                    <StackPanel Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Center"
+                                Visibility="{Binding ShowChatInactiveMessage, Converter={StaticResource BoolToVis}}">
+                        <TextBlock Text="Chat is inactive" Foreground="#a0a0b0" FontSize="13"
+                                   HorizontalAlignment="Center" Margin="0,0,0,4"/>
+                        <TextBlock Text="Chat becomes active once LlamaCasty is connected and streaming on YouTube."
+                                   Foreground="#666" FontSize="11" TextWrapping="Wrap"
+                                   HorizontalAlignment="Center" TextAlignment="Center" MaxWidth="240"/>
+                    </StackPanel>
+
+                    <!-- Message feed (shown when live) -->
+                    <ListBox Grid.Row="1" Background="Transparent" BorderThickness="0"
+                             ItemsSource="{Binding ChatMessages}"
+                             ItemContainerStyle="{StaticResource YtListBoxItem}"
+                             Visibility="{Binding ShowChatInactiveMessage, Converter={StaticResource InverseBoolToVis}}"
+                             x:Name="ChatListBox">
+                        <ListBox.ItemTemplate><DataTemplate>
+                            <Border x:Name="MessageBorder" Padding="6,4" CornerRadius="4">
+                                <Border.Style>
+                                    <Style TargetType="Border">
+                                        <Setter Property="Background" Value="Transparent"/>
+                                        <Style.Triggers>
+                                            <DataTrigger Binding="{Binding IsSuperChat}" Value="True">
+                                                <Setter Property="Background" Value="#2a1a0a"/>
+                                                <Setter Property="BorderBrush" Value="#eab308"/>
+                                                <Setter Property="BorderThickness" Value="1,0,1,0"/>
+                                            </DataTrigger>
+                                        </Style.Triggers>
+                                    </Style>
+                                </Border.Style>
+                                <StackPanel>
+                                    <StackPanel Orientation="Horizontal" Margin="0,0,0,2">
+                                        <TextBlock Text="&#x2B50;" FontSize="10" Margin="0,0,4,0"
+                                                   VerticalAlignment="Center"
+                                                   Visibility="{Binding IsMember, Converter={StaticResource BoolToVis}}"/>
+                                        <TextBlock Text="{Binding AuthorName}" Foreground="#e94560"
+                                                   FontWeight="Bold" FontSize="12" VerticalAlignment="Center"/>
+                                        <TextBlock Text="{Binding SuperChatAmount, StringFormat=${0:F2}}"
+                                                   Foreground="#eab308" FontWeight="Bold" FontSize="12"
+                                                   Margin="8,0,0,0" VerticalAlignment="Center"
+                                                   Visibility="{Binding IsSuperChat, Converter={StaticResource BoolToVis}}"/>
+                                        <TextBlock Text="{Binding SuperChatCurrency}" Foreground="#eab308"
+                                                   FontSize="11" Margin="2,0,0,0" VerticalAlignment="Center"
+                                                   Visibility="{Binding IsSuperChat, Converter={StaticResource BoolToVis}}"/>
+                                    </StackPanel>
+                                    <TextBlock Text="{Binding Message}" Foreground="#e0e0e0"
+                                               TextWrapping="Wrap" Margin="0,2,0,0"/>
+                                </StackPanel>
+                            </Border>
+                        </DataTemplate></ListBox.ItemTemplate>
+                    </ListBox>
+                </Grid>
+            </Grid>
+    </Border>
+</UserControl>

Controls/LeftPanel.xaml.cs

@@ -0,0 +1,310 @@
+using System.Collections;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using System.Windows.Media;
+using ytLive.Models;
+using ytLive.ViewModels;
+
+namespace ytLive.Controls;
+
+public partial class LeftPanel : UserControl
+{
+    private Models.SceneElement? _snapshotElement;
+    private string _snapshotBorderColor = string.Empty;
+    private int _snapshotBorderWidth;
+    private int _snapshotTimerMinutes = 15;
+    private string? _snapshotWebUri;
+
+    private Point _dragStartPoint;
+    private int _dragIndex = -1;
+    private bool _isDragging;
+    private object? _lastHoveredItem;
+
+    public LeftPanel()
+    {
+        InitializeComponent();
+        Loaded += (_, _) =>
+        {
+            if (DataContext is MainViewModel vm)
+                vm.ChatMessages.CollectionChanged += OnChatMessagesChanged;
+        };
+        Unloaded += (_, _) =>
+        {
+            if (DataContext is MainViewModel vm)
+                vm.ChatMessages.CollectionChanged -= OnChatMessagesChanged;
+        };
+    }
+
+    // Called by the window's UpdateSelectionOverlay (edit mode only).
+    public void OnSelectionChanged(MainViewModel vm)
+    {
+        if (vm.SelectedElement is { } s && PreviewPane.IsDraggableElement(s))
+            OpacityValueText.Text = $"{Math.Round(s.Opacity * 100)}%";
+        TakeSnapshot(vm);
+    }
+
+    // Deselection guard: true when the click is inside the source list or the
+    // element property scroller (window's Window_PreviewMouseLeftButtonDown).
+    public bool IsClickInside(DependencyObject original)
+        => IsDescendantOf(original, SourceList) || IsDescendantOf(original, ElementsScrollViewer);
+
+    private static bool IsDescendantOf(DependencyObject? child, DependencyObject ancestor)
+    {
+        while (child != null && !ReferenceEquals(child, ancestor))
+        {
+            child = child is Visual or System.Windows.Media.Media3D.Visual3D
+                ? VisualTreeHelper.GetParent(child)
+                : LogicalTreeHelper.GetParent(child);
+        }
+        return child != null;
+    }
+
+    private void SourceNameBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
+    {
+        if (sender is TextBox { IsVisible: true } box)
+        {
+            box.Focus();
+            box.SelectAll();
+        }
+    }
+
+    private void AddSourceButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (sender is Button { ContextMenu: { } menu } button)
+        {
+            menu.PlacementTarget = button;
+            menu.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;
+            menu.IsOpen = true;
+        }
+    }
+
+    private void OnChatMessagesChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
+    {
+        if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
+        {
+            ChatListBox.ScrollIntoView(ChatListBox.Items[^1]);
+        }
+    }
+
+    private void MirrorButton_Click(object sender, RoutedEventArgs e)
+    {
+        if ((DataContext as MainViewModel)?.SelectedElement is WebcamSceneConfig webcam)
+            webcam.IsMirrored = !webcam.IsMirrored;
+    }
+
+    private void ShapeButton_Click(object sender, RoutedEventArgs e)
+    {
+        if ((DataContext as MainViewModel)?.SelectedElement is WebcamSceneConfig webcam)
+            webcam.ToggleClipShape();
+    }
+
+    private void SourceMenu_Remove(object sender, RoutedEventArgs e)
+    {
+        if (sender is MenuItem { DataContext: SceneElement element } && DataContext is MainViewModel vm)
+            vm.RemoveSourceCommand.Execute(element);
+    }
+
+    private void BackgroundMenu_ChangeCapture(object sender, RoutedEventArgs e)
+    {
+        _ = (DataContext as MainViewModel)?.ChangeBackgroundCaptureAsync();
+    }
+
+    private void BackgroundMenu_RefreshCapture(object sender, RoutedEventArgs e)
+    {
+        (DataContext as MainViewModel)?.RefreshBackgroundAutoCapture();
+    }
+
+    private void OpacitySlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
+        => OpacityValueText.Text = $"{Math.Round(e.NewValue * 100)}%";
+
+    private void SourceNameBox_KeyDown(object sender, KeyEventArgs e)
+    {
+        if (e.Key is Key.Enter or Key.Escape)
+        {
+            CommitSourceEdit(sender);
+            e.Handled = true;
+        }
+    }
+
+    private void SourceNameBox_LostFocus(object sender, RoutedEventArgs e)
+    {
+        CommitSourceEdit(sender);
+    }
+
+    private static void CommitSourceEdit(object sender)
+    {
+        if (sender is FrameworkElement { DataContext: SceneElement element })
+            element.IsEditing = false;
+    }
+
+    // ─── List drag-to-reorder (scenes list + sources list) ───
+    private void List_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
+    {
+        var listBox = (ListBox)sender;
+        var item = FindItemContainerAt(listBox, e.GetPosition(listBox));
+        if (item == null)
+        {
+            if (ReferenceEquals(listBox, SourceList))
+                (DataContext as MainViewModel)!.SelectedElement = null;
+            _dragIndex = -1;
+            return;
+        }
+        if (listBox.ItemsSource is not IList items || items.Count == 0)
+        {
+            _dragIndex = -1;
+            return;
+        }
+        _dragIndex = listBox.Items.IndexOf(item.DataContext);
+        _dragStartPoint = e.GetPosition(listBox);
+        _isDragging = false;
+        _lastHoveredItem = null;
+    }
+
+    private void List_PreviewMouseMove(object sender, MouseEventArgs e)
+    {
+        if (_dragIndex < 0) return;
+        var listBox = (ListBox)sender;
+        if (e.LeftButton != MouseButtonState.Pressed || listBox.ItemsSource is not IList items)
+        {
+            EndListDrag(listBox);
+            return;
+        }
+
+        var position = e.GetPosition(listBox);
+        if (!_isDragging)
+        {
+            if (Math.Abs(position.X - _dragStartPoint.X) < SystemParameters.MinimumHorizontalDragDistance &&
+                Math.Abs(position.Y - _dragStartPoint.Y) < SystemParameters.MinimumVerticalDragDistance)
+                return;
+            _isDragging = true;
+            listBox.CaptureMouse();
+        }
+
+        var item = FindItemContainerAt(listBox, position);
+        if (item == null) return;
+
+        var targetItem = item.DataContext;
+        if (ReferenceEquals(targetItem, items[_dragIndex]) || ReferenceEquals(targetItem, _lastHoveredItem))
+            return;
+
+        var targetIndex = listBox.Items.IndexOf(targetItem);
+        if (targetIndex < 0) return;
+
+        var dragged = items[_dragIndex];
+        items.RemoveAt(_dragIndex);
+        items.Insert(targetIndex, dragged);
+        _dragIndex = targetIndex;
+        _lastHoveredItem = targetItem;
+    }
+
+    private void List_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
+    {
+        EndListDrag((ListBox)sender);
+    }
+
+    private void EndListDrag(ListBox listBox)
+    {
+        if (_isDragging)
+            listBox.ReleaseMouseCapture();
+        _dragIndex = -1;
+        _isDragging = false;
+        _lastHoveredItem = null;
+    }
+
+    private static ListBoxItem? FindItemContainerAt(ListBox listBox, Point position)
+    {
+        var hit = listBox.InputHitTest(position) as DependencyObject;
+        while (hit != null && hit != listBox)
+        {
+            if (hit is ListBoxItem item) return item;
+            hit = VisualTreeHelper.GetParent(hit);
+        }
+        return null;
+    }
+
+    private void TakeSnapshot(MainViewModel vm)
+    {
+        if (vm.SelectedElement is Models.Source src)
+        {
+            _snapshotElement = src;
+            _snapshotBorderColor = src.BorderColor;
+            _snapshotBorderWidth = src.BorderWidth;
+            _snapshotTimerMinutes = src.TimerMinutes;
+            _snapshotWebUri = src.WebUri;
+        }
+    }
+
+    private void WebcamBorderColorPicker_Click(object sender, RoutedEventArgs e)
+    {
+        if ((DataContext as MainViewModel)?.SelectedElement is not SceneElement src) return;
+        if (sender is FrameworkElement fe && fe.ContextMenu == null)
+        {
+            var menu = new System.Windows.Controls.ContextMenu();
+            string[] colors = ["#FFFFFF", "#000000", "#FF0000", "#00FF00", "#0000FF",
+                               "#FFFF00", "#FF00FF", "#00FFFF", "#FF8800", "#8800FF",
+                               "#e94560", "#22c55e", "#3b82f6", "#f59e0b"];
+            foreach (var c in colors)
+            {
+                var item = new System.Windows.Controls.MenuItem { Header = c, ToolTip = c };
+                var brush = new System.Windows.Media.SolidColorBrush(
+                    (System.Windows.Media.Color)System.Windows.Media.ColorConverter.ConvertFromString(c));
+                item.Icon = new System.Windows.Controls.Border
+                {
+                    Width = 16, Height = 16,
+                    Background = brush,
+                    CornerRadius = new System.Windows.CornerRadius(2)
+                };
+                var color = c;
+                item.Click += (_, _) => src.BorderColor = color;
+                menu.Items.Add(item);
+            }
+            fe.ContextMenu = menu;
+        }
+        if (sender is FrameworkElement fe2)
+            fe2.ContextMenu.IsOpen = true;
+    }
+
+    private void WebcamBorderRevert_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+        {
+            src.BorderColor = _snapshotBorderColor;
+            src.BorderWidth = _snapshotBorderWidth;
+        }
+    }
+
+    private void WebcamBorderAccept_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+        {
+            _snapshotBorderColor = src.BorderColor;
+            _snapshotBorderWidth = src.BorderWidth;
+        }
+    }
+
+    private void CountdownRevert_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+            src.TimerMinutes = _snapshotTimerMinutes;
+    }
+
+    private void CountdownAccept_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+            _snapshotTimerMinutes = src.TimerMinutes;
+    }
+
+    private void WebRevert_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+            src.WebUri = string.Empty;
+        _snapshotWebUri = string.Empty;
+    }
+
+    private void WebAccept_Click(object sender, RoutedEventArgs e)
+    {
+        if (_snapshotElement is Models.Source src)
+            _snapshotWebUri = src.WebUri;
+    }
+}

Controls/OverlayHost.xaml

@@ -0,0 +1,172 @@
+<UserControl x:Class="ytLive.Controls.OverlayHost"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:Helpers="clr-namespace:ytLive.Helpers">
+        <Grid Grid.RowSpan="3"
+              Visibility="{Binding IsAnyOverlayOpen, Converter={StaticResource BoolToVis}}">
+            <Button Background="#99000000" BorderThickness="0" Cursor="Hand"
+                    Command="{Binding CloseOverlayCommand}">
+                <Button.Template>
+                    <ControlTemplate TargetType="Button">
+                        <Border Background="{TemplateBinding Background}"/>
+                    </ControlTemplate>
+                </Button.Template>
+            </Button>
+
+            <Border Background="#0A0C1A" CornerRadius="8" Width="650" MaxHeight="700"
+                    VerticalAlignment="Center" HorizontalAlignment="Center"
+                    Padding="28" BorderBrush="#333" BorderThickness="1">
+                <Grid>
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto"/>
+                        <RowDefinition Height="Auto"/>
+                    </Grid.RowDefinitions>
+
+                    <!-- Header -->
+                    <Grid Grid.Row="0">
+                        <TextBlock Text="{Binding OverlayTitle}" FontSize="18" FontWeight="Bold"
+                                   Foreground="#e0e0e0" VerticalAlignment="Center"/>
+                        <Button HorizontalAlignment="Right" ToolTip="Close" Style="{StaticResource IconButton}"
+                                Command="{Binding CloseOverlayCommand}">
+                            <Path Data="M19,6.41L17.59,5 12,10.59 6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 12,13.41 17.59,19 19,17.59 13.41,12z"
+                                  Fill="#d0d0d0" Width="14" Height="14" Stretch="Uniform"/>
+                        </Button>
+                    </Grid>
+
+                    <!-- App Settings: broadcast fields live in the preview's
+                         Text pull-out now — this panel keeps app-level prefs only.
+                         (Currently empty; the overlay shell stays for future use.) -->
+                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
+                                Visibility="{Binding IsSettingsOpen, Converter={StaticResource BoolToVis}}">
+                        <TextBlock Text="Default Location for Recordings" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                        <TextBox Style="{StaticResource YtTextBox}" 
+                                 Text="{Binding RecordFolderDisplay, Mode=OneWay}"
+                                 IsReadOnly="True" Margin="0,0,0,12" Foreground="#a0a0b0"/>
+                        <StackPanel Orientation="Horizontal">
+                            <Button Content="Browse…" Command="{Binding ChooseRecordFolderCommand}"
+                                    Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
+                            <Button Content="Use Downloads" Command="{Binding ResetRecordFolderCommand}"
+                                    Style="{StaticResource YtButtonSecondary}"/>
+                        </StackPanel>
+                    </StackPanel>
+
+                    <!-- Report Bug -->
+                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
+                                Visibility="{Binding IsBugOpen, Converter={StaticResource BoolToVis}}">
+                        <TextBlock Text="What went wrong?" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                        <TextBox Style="{StaticResource YtTextBox}" Height="110" AcceptsReturn="True" TextWrapping="Wrap"
+                                 Margin="0,0,0,12"
+                                 Text="{Binding BugReportText, UpdateSourceTrigger=PropertyChanged}"
+                                 VerticalScrollBarVisibility="Auto"/>
+
+                        <TextBlock Text="Email (optional)" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                        <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
+                                 Text="{Binding BugReportEmail, UpdateSourceTrigger=PropertyChanged}"/>
+
+                        <TextBlock Text="Opens a pre-filled email to the LlamaCasty team." Style="{StaticResource YtLabel}"/>
+                        <Button Content="Send Report" Command="{Binding SubmitBugCommand}"
+                                Style="{StaticResource YtButton}" HorizontalAlignment="Right" Margin="0,16,0,0"/>
+                    </StackPanel>
+
+                    <!-- Feature Request -->
+                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
+                                Visibility="{Binding IsFeatureOpen, Converter={StaticResource BoolToVis}}">
+                        <TextBlock Text="What would you like to see?" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                        <TextBox Style="{StaticResource YtTextBox}" Height="110" AcceptsReturn="True" TextWrapping="Wrap"
+                                 Margin="0,0,0,12"
+                                 Text="{Binding FeatureRequestText, UpdateSourceTrigger=PropertyChanged}"
+                                 VerticalScrollBarVisibility="Auto"/>
+
+                        <TextBlock Text="Email (optional)" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                        <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
+                                 Text="{Binding FeatureRequestEmail, UpdateSourceTrigger=PropertyChanged}"/>
+
+                        <TextBlock Text="Opens a pre-filled email to the LlamaCasty team." Style="{StaticResource YtLabel}"/>
+                        <Button Content="Send Request" Command="{Binding SubmitFeatureCommand}"
+                                Style="{StaticResource YtButton}" HorizontalAlignment="Right" Margin="0,16,0,0"/>
+                    </StackPanel>
+
+                    <!-- About -->
+                    <Grid Grid.Row="1" Margin="0,16,0,0"
+                          Background="#171928"
+                          Visibility="{Binding IsAboutOpen, Converter={StaticResource BoolToVis}}">
+
+                        <!-- Hub view -->
+                        <StackPanel Visibility="{Binding IsHubVisible, Converter={StaticResource BoolToVis}}">
+                            <Image Source="/ytLive;component/Assets/llamacasty-logo.jpg" Height="125" Stretch="Uniform"
+                                   HorizontalAlignment="Center" Margin="0,0,0,12"/>
+                            <TextBlock Text="{Binding AppVersionLabel}" Foreground="#a0a0b0" FontSize="12"
+                                       HorizontalAlignment="Center" Margin="0,4,0,0"/>
+                            <TextBlock Text="Live streaming for YouTube — simple enough that even the most right-brained person can intuit it."
+                                       Foreground="#a0a0b0" FontSize="13" TextWrapping="Wrap" MaxWidth="380"
+                                       TextAlignment="Center" Margin="0,16,0,0"/>
+                            <TextBlock Text="Free forever — live streams carry a brief &quot;made with LlamaCasty!&quot; flash. A subscription removes it and adds alerts."
+                                       Foreground="#888" FontSize="12" TextWrapping="Wrap" MaxWidth="380"
+                                       TextAlignment="Center" Margin="0,12,0,0"/>
+                            <TextBlock Text="Made by gramps · llama chile shop" Foreground="#a0a0b0" FontSize="12"
+                                       HorizontalAlignment="Center" Margin="0,16,0,8"/>
+
+                            <!-- Creator hub links -->
+                            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,0,0,8">
+                                <Button Content="llama chile shop on YouTube" Command="{Binding OpenChannelCommand}"
+                                        Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
+                                <Button Content="Mastodon" Command="{Binding OpenMastodonCommand}"
+                                        Style="{StaticResource YtButtonSecondary}"/>
+                            </StackPanel>
+                            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
+                                <Button Content="Buy me a coffee" Command="{Binding OpenCoffeeCommand}"
+                                        Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
+                                <Button Content="Unlock Premium" Command="{Binding OpenPremiumCommand}"
+                                        Style="{StaticResource YtButtonSecondary}"
+                                        IsEnabled="{Binding IsPremiumAvailable}"
+                                        ToolTip="Open the LlamaCasty subscription page"/>
+                                <Button Content="Enter License Key" Command="{Binding OpenLicenseEntryCommand}"
+                                        Style="{StaticResource YtButtonSecondary}"
+                                        ToolTip="Activate a license key to remove the watermark"/>
+                            </StackPanel>
+
+                            <Button Content="Licenses &amp; legal" Command="{Binding OpenLicensesCommand}"
+                                    Style="{StaticResource YtButtonSecondary}" HorizontalAlignment="Center"
+                                    Margin="0,16,0,0"/>
+                        </StackPanel>
+
+                        <!-- Licensing/legal panel -->
+                        <StackPanel Visibility="{Binding IsLicensesOpen, Converter={StaticResource BoolToVis}}">
+                            <TextBlock Text="Third-party notices &amp; license texts" FontSize="15" FontWeight="Bold"
+                                       Foreground="#e0e0e0" Margin="0,0,0,8"/>
+                            <Border Background="#10101e" CornerRadius="4" Padding="10" MaxHeight="360"
+                                    BorderBrush="#333" BorderThickness="1">
+                                <ScrollViewer VerticalScrollBarVisibility="Auto">
+                                    <TextBlock Text="{Binding LicensesText}" Foreground="#b8b8c8" FontSize="11"
+                                               FontFamily="Consolas" TextWrapping="Wrap"/>
+                                </ScrollViewer>
+                            </Border>
+                            <Button Content="← Back to About" Style="{StaticResource YtButtonSecondary}"
+                                    HorizontalAlignment="Left" Margin="0,12,0,0"
+                                    Click="BackToAbout_Click"/>
+                        </StackPanel>
+
+                        <!-- License key entry panel -->
+                        <StackPanel Visibility="{Binding IsLicenseEntryOpen, Converter={StaticResource BoolToVis}}">
+                            <TextBlock Text="Activate LlamaCasty Premium" FontSize="15" FontWeight="Bold"
+                                       Foreground="#e0e0e0" Margin="0,0,0,8"/>
+                            <TextBlock Text="Enter your license key to remove the branding watermark."
+                                       Foreground="#a0a0b0" FontSize="12" TextWrapping="Wrap" Margin="0,0,0,12"/>
+                            <TextBlock Text="License Key" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
+                            <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
+                                     Text="{Binding LicenseKey, UpdateSourceTrigger=PropertyChanged}"
+                                     MaxLength="100"/>
+                            <Button Content="Activate" Command="{Binding ActivateLicenseCommand}"
+                                    Style="{StaticResource YtButton}" HorizontalAlignment="Right"
+                                    Margin="0,0,0,8"/>
+                            <TextBlock Text="{Binding LicenseMessage}" Foreground="#a0a0b0" FontSize="12"
+                                       TextWrapping="Wrap" Margin="0,0,0,8"/>
+                            <Button Content="← Back to About" Style="{StaticResource YtButtonSecondary}"
+                                    HorizontalAlignment="Left" Margin="0,8,0,0"
+                                    Click="BackToAbout_Click"/>
+                        </StackPanel>
+                    </Grid>
+                </Grid>
+            </Border>
+        </Grid>
+</UserControl>

Controls/OverlayHost.xaml.cs

@@ -0,0 +1,22 @@
+using System.Windows;
+using System.Windows.Controls;
+using ytLive.ViewModels;
+
+namespace ytLive.Controls;
+
+public partial class OverlayHost : UserControl
+{
+    public OverlayHost()
+    {
+        InitializeComponent();
+    }
+
+    private void BackToAbout_Click(object sender, RoutedEventArgs e)
+    {
+        if (DataContext is MainViewModel vm)
+        {
+            vm.IsLicensesOpen = false;
+            vm.IsLicenseEntryOpen = false;
+        }
+    }
+}

Controls/index.md

@@ -0,0 +1,58 @@
+# Controls — index
+
+The phase-2 carved pieces of what used to be one monolithic `MainWindow.xaml`
+(1,681 lines → a 123-line shell). Each is a `UserControl` in the `ytLive.Controls`
+namespace, extracted one roll-back commit at a time (refactor-commit-12..18).
+See [`schema.md`](../schema.md) for the memory-map conventions.
+
+| File | Purpose |
+|------|---------|
+| `BottomBar.xaml(.cs)` | Footer (Row 3): gear menu (stop/mic/game-mute/quality dropdown), stream stats (bitrate/fps/dropped/duration/health), resolution dropdown |
+| `HealthBanner.xaml(.cs)` | Row 1 status banner + the 7 value→visibility converters live in the app theme, not here |
+| `TopBar.xaml(.cs)` | Row 0 stream controls: REC/ON-AIR pills+signs, elapsed timer, start/stop, account avatar/name (`RefreshAvatar()`) |
+| `PreviewPane.xaml(.cs)` | Row 1 Col 1 center: the 1920×1080 `OverlayCanvas`/`SelectionOverlay`/`BrandFlashLayer`/`SocialBarElement`, text pull-out drawer, and the live-controls row (TRAX / game / mic meters + sliders + speakers + socials) |
+| `SceneThumbnailStrip.xaml(.cs)` | Row 0 scene-picker strip (`ItemsControl` over `Scenes`), staged-red / live-green border highlight |
+| `LeftPanel.xaml(.cs)` | Row 1 Col 0 left panel: edit mode → layers+properties; live → YouTube chat. Source add/edit/remove, list drag-to-reorder, snapshot revert-accept |
+| `OverlayHost.xaml(.cs)` | Root-grid overlay dialogs: Settings / Report Bug / Feature Request / About (+ licenses + license-key entry). `BackToAbout_Click` lives here |
+| `SceneThumbnailStrip.xaml.cs` | Code-behind for the strip above |
+| `LeftPanel.xaml.cs` | Code-behind for the panel above |
+
+## Window ↔ control contract
+
+The shell (`MainWindow.xaml(.cs)`) wires up each control and routes the few
+cross-cutting calls through it:
+
+- Ctor finds each control by `x:Name` (`TopBar`, `PreviewPane`, `LeftPanel`)
+  AFTER `InitializeComponent`, **before** any method touches it (null-ref guard).
+- `_previewPane.IsClickInsidePreview/Drawer` + `_leftPanel.IsClickInside` →
+  deselection guard in `Window_PreviewMouseLeftButtonDown`.
+- `_previewPane.UpdateSelectionOverlay(bool)` + `_leftPanel.OnSelectionChanged(vm)`
+  → selection/edit-mode routing from the VM's `SelectedElement` change.
+- `_topBar.RefreshAvatar()` on `IsConnected`/`AccountAvatarUrl` change.
+- Handlers in moved controls cast `(DataContext as MainViewModel)` — controls
+  inherit the window's DataContext; never pass the VM through a property.
+
+## Gotchas learned the hard way
+
+- **A UserControl cannot see `Window.Resources`** (StaticResource resolves by
+  element lookup, so it stops at the control boundary). The 7 converters
+  (`BoolToVis`, `InverseBoolToVis`, `NotNullToVis`, `NullToVis`, `HiddenBoolToVis`,
+  `EnumToBool`, `AllTrueToVis`) were promoted from `MainWindow.Resources` into
+  `Themes/Controls.xaml` (see [`Themes/index.md`](../Themes/index.md)).
+- **Moved XAML can lose its namespace**: a block cut from MainWindow carries no
+  root xmlns, so any `models:`/`Helpers:` ref in it breaks the build with
+  `MC2000: Value cannot be null (key)`. Declare `xmlns:models` / `xmlns:Helpers`
+  on each control's root (LeftPanel hit this).
+- **Name-looked-up host stubs must stay in the window**, not a control:
+  `WebViewHostPanel` (ctor `InitWebView2(WebViewHostPanel)`) and `ToastArea`
+  (`NotificationService.InArea("ToastArea")`) are resolved by name from the
+  window root — so `OverlayHost` deliberately leaves them as thin window-root
+  children (Commit 18).
+- When cutting visual wrappers, don't drop the outer `Border`'s
+  background/glow/margin — Commit 15 initially lost the preview's outer border
+  and had to restore it same-commit.
+
+Related: [`ViewModels/index.md`](../ViewModels/index.md) (MainViewModel the
+controls bind to), [`Themes/index.md`](../Themes/index.md) (styles/converters),
+[`Helpers/index.md`](../Helpers/index.md) (ViewModelBase, converters), the
+`MainWindow.xaml` shell at repo root that hosts these.

HANDOFF.md

@@ -2,41 +2,50 @@
 
 ## Branch / Commit State
 
-**`main`**, working tree is **CLEAN**.
+**`main`**, working tree is **CLEAN**. `origin/main` == `1f4624c` (pushed).
 
-Commits `46978b8` (AGENTS push policy), `fc33022` (HANDOFF), and refactor
-commits `0–5` through `e286719` are **pushed** (incl. `refactor-commit-0..5`).
-Refactor commits **6–11 are LOCAL ONLY** (policy 2026-08-30: no per-commit
-push; `git push --tags` only at a user-agreed milestone / "push it"):
+**Pushed** (reached `origin/main` == `1f4624c`, incl. tags): Phase 1 commit `0`
++ refactor commits `1..11`, **and Phase 2 commits `12..18`** (they were pushed
+at the Phase-2 milestone; the old "Phase 2 local-only" claim below was written
+before that push and is stale).
 
-| Commit | Hash | Tag | Partial | Lines |
-|--------|------|-----|---------|-------|
-| 6 Audio | `c1126a5` | `refactor-commit-6` | `MainViewModel.Audio.cs` | 408 |
-| 7 Trax | `535a501` | `refactor-commit-7` | `MainViewModel.Trax.cs` | 132 |
-| 8 Socials | `c41ff7f` | `refactor-commit-8` | `MainViewModel.Socials.cs` | 161 |
-| 9 Streaming | `e1006a0` | `refactor-commit-9` | `MainViewModel.Streaming.cs` | 787 |
-| 10 Chat | `3b77a13` | `refactor-commit-10` | `MainViewModel.Chat.cs` | 194 |
-| 11 Overlays | `1efde5a` | `refactor-commit-11` | `MainViewModel.Overlays.cs` | 194 |
+**LOCAL ONLY (Phase 3 — A, B, C, D, E) + the Controls doc commit** — policy
+2026-08-30: no per-commit push; `git push` only at a user-agreed milestone /
+"push it". **Push pending on explicit user approval:**
 
-Nightly summary: **Phase 1 complete.** The plan was 11 partials + scaffold;
-all live in `ViewModels/`. Core `MainViewModel.cs` shrank 1,890 → **758
-lines**. Every change: clean build (0 warnings), `scripts/verify.sh` (246
-passed + 2 known failures only), `scripts/scope-check.sh` with explicit file
-args, `ViewModels/index.md` updated in the SAME commit, tagged
-`refactor-commit-N`, no per-commit push.
+| Commit | Hash | Tag | Payload |
+|--------|------|-----|---------|
+| docs | `cb54637` | — | `Controls/index.md` (missing per-directory map) |
+| A | `6944db8` | `refactor-commit-A` | split `MainViewModel.cs` core → **495** |
+| B | `31362d1` | `refactor-commit-B` | split `MainViewModel.Streaming.cs` → **330** |
+| C | `fab2e09` | `refactor-commit-C` | split `MainViewModel.Background.cs` → **418** |
+| D | `d3271a0` | `refactor-commit-D` | trim `SocialsDialogViewModel.cs` → **334** |
+| E | `dcb3637` | `refactor-commit-E` | split `LayoutStore.cs` → 6 partials, **≤495** |
 
 ## What's In Flight
 
-Nothing code-in-flight — working tree clean, Phase 1 done.
+Nothing code-in-flight — working tree clean, **Phase 3 complete**.
 
-**Next (queued, not started): Phase 2 — split `MainWindow.xaml` (1,681 lines)
-into UserControls.** Same rules: one work unit per control, docs in the same
-commit, verify + scope-check, commit locally, `git push` only on user go.
+**Phase 3 result:** every production `.cs` is now **≤ 500 lines** (checked via
+`git ls-files '*.cs'` minus tests; nothing exceeds 500). The 500-line count is a
+**hard ceiling, not the goal** — each file was split **grouped by functionality**
+so an AI can process one concern per file. Splits were **concern-driven**:
+- `MainViewModel` → `.Sources.cs`/`.Web.cs`, `Streaming.cs` + `Streaming.Operations.cs`,
+  `Background.cs` + `Background.Model.cs`; `SocialSlotViewModel.cs` (row VM).
+- `LayoutStore` (was 1402) → `Migrations.cs`/`Load.cs`/`Save.cs`/`Settings.cs`/
+  `Assets.cs` + a 47-line shell; `public partial class LayoutStore : IDisposable`.
 
-**Push pending:** refactor commits 6–11 + their tags are local. The Session-1
-push checkpoint was never reached because the user directive was to run the
-series to completion; Phase 1 completion is the natural milestone to push on
-explicit user confirmation.
+Every change: 0-warning build, `scripts/verify.sh` (246 pass + 2 known only),
+explicit-file `scripts/scope-check.sh`, `ViewModels/index.md` tracker in the
+SAME commit, tagged `refactor-commit-N`, no per-commit push.
+
+**Next:** 
+- If user says "push": `git push origin main && git push --tags` (6 commits:
+  `cb54637` + A–E, and tags `refactor-commit-A..E`).
+
+**Pending bus:** `ViewModels/index.md` Phase 3 tracker has rows A–E (closed);
+Phase 3 marked COMPLETE. Watch-list (under limit, no action): `Controls/PreviewPane.xaml.cs`
+(464), `ViewModels/MainViewModel.Audio.cs` (408).
 
 ## Landmines
 
@@ -45,44 +54,49 @@ explicit user confirmation.
   `RoundClipInteractionTests.Round_Clip_Corner_Is_Grabbable_And_Shape_Is_Circle`.
 - **Tests occasionally abort early (236/237)** — known flake, accepted by `verify.sh`.
 - **App running locks `ytLive.exe`** → build fails MSB3027. Kill PID before building.
-- **Implicit usings are SDK-default but partials must still carry their own
-  domain usings** (they do not inherit core's): `ICommand`/`ObservableCollection`/
-  `WriteableBitmap`/`DispatcherTimer` etc. are NOT implicit. Grep-verified usings:
-  - Audio: Input, Media, Threading, `NAudio.CoreAudioApi`, `ytLive`, Helpers, Models, Services, Services.Audio
-  - Trax: IO, Media, `Microsoft.Win32`, Helpers, Models, Services.Audio
-  - Socials: Windows, Input, Media, `ytLive`, Helpers, Models, Services, Services.Compositor
-  - Streaming: ObjectModel, IO, Windows, Input, Threading, `Microsoft.Win32`, Helpers, Models, Services, Services.Encoder
-  - Chat: ObjectModel, Media, Media.Imaging, Threading, Helpers, Models, Services
-  - Overlays: Diagnostics, IO, Input, Helpers
+- **WinForm crash from `Window_PreviewMouseLeftButtonDown`** — handled in-side the
+  preview/left panel; don't add handlers that deref `OriginalSource` unguarded.
+- **Controls cannot see `Window.Resources`** (converter rule, Commit 13): any
+  StaticResource the window once supplied must live at app level in
+  `Themes/Controls.xaml`. The 7 converters were promoted there.
+- **Some control XAML needs its own `xmlns:models` / `xmlns:Helpers`** — a moved
+  block lost its namespace when it left MainWindow's root (LeftPanel hit this,
+  MC2000 "key null"). Always add the model/helper xmlns on each control root.
+- **Name-looked-up host stubs must stay in the window:** `WebViewHostPanel`
+  (ctor `InitWebView2(WebViewHostPanel)`) and `ToastArea`
+  (`NotificationService.InArea("ToastArea")`) are resolved by name from the
+  window — keep them as window-root children, don't bury them in a control.
+  OverlayHost deliberately left them in place (Commit 18) for this reason.
 - **Pre-commit gate:** `scripts/verify.sh` (0-warning build + full tests) and
   `scripts/scope-check.sh "file1" …` — scope-check REQUIRES explicit file args.
 - Build from WSL with the Windows dotnet host only (see `AGENTS.md`).
 
 ## Todo state
 
-- MainViewModel refactor: **Phase 1 complete (11/11 partials + scaffold).**
-  `ViewModels/index.md` has a per-partial table row (code↔commit map in the
-  tracker section). Core row now describes only what remains (ctor wiring,
-  lifecycle, source commands, WebView2 hosting, frame-pump seam,
-  `SelectedElement`, `BrandFlash*`, `BuildCompositorOptions`/`ResolveOutputFrame`).
+- MainViewModel refactor: **Phase 1 complete (11/11 partials)**, pushed.
+- MainWindow.xaml refactor: **Phase 2 complete (6/6 controls)**, pushed at `1f4624c`.
+- 500-line compliance: **Phase 3 complete (all 5 offenders ≤ 500)**, local-only A–E.
 - TASK 3: 27/30 (preview compositor 16, text source 17, alerts 20 still open).
 - TASK 4: ✅ shipped. TASK 9: items 1–3 shipped; 4–7 open. TASK 10: steps 1–7; Velopack pending.
 - TASK 18: shipped, creator verification pending. TASK 19/23, 20, 21-A: shipped.
 - TASK 22 (audio sync offset): not started — required for v1.
-- Monitoring: cross-partial private access is the point of partial classes —
-  no moved member re-declared anywhere; moved setters reference other partials
-  purely by name.
 
-## Session summary (2026-08-30)
+## Session summary (2026-08-31)
 
-- Ran the MainViewModel split to completion under the standing directive
-  ("continue until you can continue no longer" — no interruption prompts).
-- Commits 9 (Streaming), 10 (Chat), 11 (Overlays) landed locally, each ~8:40
-  back-to-back: cut → 0-warning build → verify (246 pass + 2 known) →
-  scope-check → index.md in-commit → `git tag refactor-commit-N`. No push.
-- Streaming was the hardest cut (interleaved props, master-frame consts,
-  session timer, health pipeline, record rename-on-stop); Chat and Overlays
-  were clean contiguous cuts. One build fix each: Streaming needed
-  `ObjectModel`/`Input`, Chat needed `Media.Imaging` for `WriteableBitmap`.
-- Docs kept honest throughout: `index.md` rows for Streaming/Chat/Overlays,
-  About-hub row re-pointed to the Overlays partial, core row trimmed each time.
+- Ran the **500-line Phase 3 split to completion** under the standing "continue
+  without stopping" directive — no interruption prompts, no `question` tool.
+- Commits A–E landed locally, each: cut → 0-warning build → verify (246 pass + 2
+  known) → scope-check → index.md in-commit → `git tag refactor-commit-{A..E}`.
+- **Re-structuring principle (user correction, 2026-08-31):** split by
+  **functionality**, so an AI can process one concern per file; the 500-line
+  count is a **ceiling**, NOT the target. Do not pad or reshape code to a
+  number — group by concern and only split enough to stay under the ceiling.
+- **Commit E (LayoutStore)** the biggest: 1402 → 6 concern-based partials
+  (Migrations/Load/Save/Settings/Assets/shell), default partial split.
+- **Accident caught & recovered (Commit D):** a `> ViewModels/SocialsDialogViewModel.cs`
+  write that read from the file it was simultaneously truncating left the file at
+  1 line. Fixed IMMEDIATELY via `git checkout --` and re-ran the split. **Lesson**
+  (goes in `MyMistakes.md`): never `awk … > SRC` where `awk` also reads `SRC`;
+  stage every multi-block cut into temp files first, then assemble. All later
+  LayoutStore cuts did exactly that (read original once into temp files).
+- Push checkpoint reached; awaiting explicit "push" for `cb54637` + A–E + tags.

MainWindow.xaml

@@ -98,499 +98,8 @@
             <!-- LEFT PANEL: one panel, two states.
                  Offline (edit mode): LAYERS + PROPERTIES
                  Live/Recording: YouTube Live Chat -->
-            <Border Grid.Row="1" Grid.Column="0" Background="#16213e" CornerRadius="6" Padding="12">
-                <Grid>
-                    <Grid.RowDefinitions>
-                        <RowDefinition Height="*"/>
-                    </Grid.RowDefinitions>
+            <controls:LeftPanel x:Name="LeftPanel" Grid.Row="1" Grid.Column="0"/>
 
-                    <!-- Edit mode (offline): layers + properties -->
-                    <Grid Grid.Row="0" Visibility="{Binding IsEditMode, Converter={StaticResource BoolToVis}}">
-                        <Grid.RowDefinitions>
-                            <RowDefinition Height="Auto"/>
-                            <RowDefinition Height="Auto"/>
-                            <RowDefinition Height="Auto"/>
-                            <RowDefinition Height="Auto"/>
-                            <RowDefinition Height="Auto"/>
-                            <RowDefinition Height="*"/>
-                        </Grid.RowDefinitions>
-
-                        <!-- LAYERS header + Add button -->
-                        <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="0,8,0,0">
-                            <TextBlock Text="LAYERS" Style="{StaticResource SectionHeader}" VerticalAlignment="Center"/>
-                            <Button ToolTip="Add Layer" Style="{StaticResource IconButton}" Margin="4,-4,0,0"
-                                Click="AddSourceButton_Click">
-                            <Button.ContextMenu>
-                                <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
-                                    <MenuItem Header="Webcam" Command="{Binding AddWebcamCommand}"
-                                              IsEnabled="{Binding CanAddWebcam}"
-                                              ToolTip="One webcam at a time — it's already in your stream"/>
-                                    <MenuItem Header="Image" Command="{Binding AddImageCommand}"/>
-                                    <MenuItem Header="Text" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.TextOverlay}"/>
-                                    <MenuItem Header="Countdown" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.Countdown}"
-                                              Visibility="{Binding IsCountdownAvailable, Converter={StaticResource BoolToVis}}"
-                                              ToolTip="Timer overlay — Starting and BRB screens only"/>
-                                    <MenuItem Header="Web Resource" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.WebSource}"
-                                              ToolTip="Embedded web page — set URI in Properties panel"/>
-                                    <MenuItem Header="YouTube Chat" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.ChatBox}"
-                                              IsEnabled="{Binding CanAddYouTubeChat}"
-                                              ToolTip="One chat layer at a time — it's already in your stream"/>
-                                </ContextMenu>
-                            </Button.ContextMenu>
-                            <Path Data="M12,4 L12,20 M4,12 L20,12" Stroke="#e94560" StrokeThickness="2"
-                                  Width="14" Height="14" Stretch="Uniform"/>
-                        </Button>
-                    </StackPanel>
-
-                    <Helpers:FocusPreservingListBox x:Name="SourceList" Grid.Row="1" Background="Transparent" BorderThickness="0"
-                             ItemsSource="{Binding StagedScene.Elements}"
-                             SelectedItem="{Binding SelectedElement, Mode=TwoWay}"
-                             PreviewMouseLeftButtonDown="List_PreviewMouseLeftButtonDown"
-                             PreviewMouseMove="List_PreviewMouseMove"
-                             PreviewMouseLeftButtonUp="List_PreviewMouseLeftButtonUp"
-                             Foreground="#e0e0e0" FontSize="13">
-                        <Helpers:FocusPreservingListBox.ItemContainerStyle>
-                            <Style TargetType="ListBoxItem" BasedOn="{StaticResource YtListBoxItem}">
-                                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
-                                <Style.Triggers>
-                                    <DataTrigger Binding="{Binding IsVisible}" Value="False">
-                                        <Setter Property="Opacity" Value="0.45"/>
-                                    </DataTrigger>
-                                </Style.Triggers>
-                            </Style>
-                        </Helpers:FocusPreservingListBox.ItemContainerStyle>
-                        <ListBox.ItemTemplate>
-                            <DataTemplate>
-                                <Grid Margin="0,2"
-                                      Tag="{Binding DataContext.CanChangeBackground, RelativeSource={RelativeSource AncestorType=Window}}">
-                                    <Grid.ColumnDefinitions>
-                                        <ColumnDefinition Width="*"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                        <ColumnDefinition Width="Auto"/>
-                                    </Grid.ColumnDefinitions>
-
-                                    <Grid.ContextMenu>
-                                        <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
-                                            <MenuItem Header="Change Capture…" Click="BackgroundMenu_ChangeCapture">
-                                                <MenuItem.Visibility>
-                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
-                                                        <Binding Path="IsBackground"/>
-                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
-                                                    </MultiBinding>
-                                                </MenuItem.Visibility>
-                                            </MenuItem>
-                                            <MenuItem Header="Refresh Capture" Click="BackgroundMenu_RefreshCapture">
-                                                <MenuItem.Visibility>
-                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
-                                                        <Binding Path="IsBackground"/>
-                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
-                                                    </MultiBinding>
-                                                </MenuItem.Visibility>
-                                            </MenuItem>
-                                            <Separator>
-                                                <Separator.Visibility>
-                                                    <MultiBinding Converter="{StaticResource AllTrueToVis}">
-                                                        <Binding Path="IsBackground"/>
-                                                        <Binding Path="PlacementTarget.Tag" RelativeSource="{RelativeSource AncestorType={x:Type ContextMenu}}"/>
-                                                    </MultiBinding>
-                                                </Separator.Visibility>
-                                            </Separator>
-                                            <MenuItem Header="Remove Layer" Click="SourceMenu_Remove"
-                                                      Visibility="{Binding IsBackground, Converter={StaticResource InverseBoolToVis}}"/>
-                                        </ContextMenu>
-                                    </Grid.ContextMenu>
-
-                                    <TextBlock Grid.Column="0" Text="{Binding Name}" VerticalAlignment="Center"
-                                               Padding="4,2" TextTrimming="CharacterEllipsis">
-                                        <TextBlock.Style>
-                                            <Style TargetType="TextBlock">
-                                                <Setter Property="Visibility" Value="Visible"/>
-                                                <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
-                                                        <Setter Property="Visibility" Value="Collapsed"/>
-                                                    </DataTrigger>
-                                                </Style.Triggers>
-                                            </Style>
-                                        </TextBlock.Style>
-                                    </TextBlock>
-
-                                    <TextBox Grid.Column="0" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="0"
-                                             Padding="4,2" VerticalContentAlignment="Center"
-                                             IsVisibleChanged="SourceNameBox_IsVisibleChanged"
-                                             KeyDown="SourceNameBox_KeyDown" LostFocus="SourceNameBox_LostFocus">
-                                        <TextBox.Style>
-                                            <Style TargetType="TextBox">
-                                                <Setter Property="Visibility" Value="Collapsed"/>
-                                                <Style.Triggers>
-                                                    <DataTrigger Binding="{Binding IsEditing}" Value="True">
-                                                        <Setter Property="Visibility" Value="Visible"/>
-                                                    </DataTrigger>
-                                                </Style.Triggers>
-                                            </Style>
-                                        </TextBox.Style>
-                                    </TextBox>
-
-                                    <Button Grid.Column="1" ToolTip="Edit Layer Name"
-                                            Command="{Binding DataContext.EditElementCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}">
-                                        <Path Data="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z"
-                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
-
-                                    <Button Grid.Column="2" Style="{StaticResource EyeButton}"
-                                            Command="{Binding DataContext.ToggleElementVisibilityCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}">
-                                        <Path Style="{StaticResource EyeIconStyle}" Fill="#d0d0d0"
-                                              Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
-
-                                    <Button Grid.Column="3" ToolTip="Remove Layer"
-                                            Command="{Binding DataContext.RemoveSourceCommand, RelativeSource={RelativeSource AncestorType=ListBox}}"
-                                            CommandParameter="{Binding}" Style="{StaticResource IconButton}"
-                                            Visibility="{Binding IsBackground, Converter={StaticResource HiddenBoolToVis}}">
-                                        <Path Data="M6,19c0,1.1 0.9,2 2,2h8c1.1,0 2,-0.9 2,-2V7H6v12zM19,4h-3.5l-1,-1h-5l-1,1H5v2h14V4z"
-                                              Fill="#d0d0d0" Width="13" Height="13" Stretch="Uniform"/>
-                                    </Button>
-                                </Grid>
-                            </DataTemplate>
-                        </ListBox.ItemTemplate>
-                    </Helpers:FocusPreservingListBox>
-
-                            <TextBlock Grid.Row="2" Text="No layers yet" Foreground="#555" FontSize="12"
-                               HorizontalAlignment="Center" VerticalAlignment="Center"
-                               Visibility="{Binding ShowSourcesEmptyHint, Converter={StaticResource BoolToVis}}"/>
-
-                    <!-- ELEMENTS panel: per-element config beneath Sources.
-                         Collapses entirely when no element is selected. -->
-                    <Rectangle Grid.Row="3" Height="1" Fill="#2c3a5c" Margin="0,10,0,2"
-                               Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}"/>
-                    <StackPanel Grid.Row="4" Orientation="Horizontal" Margin="0,8,0,0"
-                                Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}">
-                        <TextBlock Text="PROPERTIES" Style="{StaticResource SectionHeader}" VerticalAlignment="Center"/>
-                    </StackPanel>
-                    <ScrollViewer x:Name="ElementsScrollViewer" Grid.Row="5" VerticalScrollBarVisibility="Auto" Background="Transparent"
-                                  Visibility="{Binding SelectedElement, Converter={StaticResource NotNullToVis}}">
-                        <StackPanel x:Name="ElementsPanel" Margin="0,4,0,0">
-                            <!-- Opacity + mirror/shape (draggable elements: image, webcam) -->
-                            <StackPanel Visibility="{Binding SelectedElement.IsDraggable, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
-                                <StackPanel Visibility="{Binding SelectedElement.IsChatBox, Converter={StaticResource InverseBoolToVis}}">
-                                    <TextBlock Text="Opacity" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
-                                    <DockPanel Margin="0,0,0,6">
-                                        <TextBlock x:Name="OpacityValueText" Text="100%" Foreground="#a0a0b0" FontSize="11"
-                                                   DockPanel.Dock="Right" VerticalAlignment="Center" Margin="8,0,0,0" Width="32"/>
-                                        <Slider x:Name="OpacitySlider" Width="120" Minimum="0" Maximum="1"
-                                                Value="{Binding SelectedElement.Opacity, Mode=TwoWay}"
-                                                ValueChanged="OpacitySlider_ValueChanged" VerticalAlignment="Center"/>
-                                    </DockPanel>
-                                </StackPanel>
-                                <StackPanel Orientation="Horizontal" Margin="0,0,0,4"
-                                            Visibility="{Binding IsWebcamSelected, Converter={StaticResource BoolToVis}}">
-                                    <Button Content="{Binding SelectedElement.MirrorButtonText}"
-                                            Style="{StaticResource YtButtonSecondary}" Padding="10,4"
-                                            Click="MirrorButton_Click"/>
-                                    <Button Content="{Binding SelectedElement.ShapeButtonText}"
-                                            Style="{StaticResource YtButtonSecondary}" Padding="10,4"
-                                            Margin="8,0,0,0" Click="ShapeButton_Click"/>
-                                </StackPanel>
-                                <TextBlock Text="Drag to move · drag the corner dot to resize"
-                                           Foreground="#a0a0b0" FontSize="10" Margin="0,2,0,0"/>
-                            </StackPanel>
-
-                            <!-- Webcam border config -->
-                            <StackPanel Visibility="{Binding SelectedElement.IsWebcam, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
-                                <TextBlock Text="Border Color" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
-                                <DockPanel Margin="0,0,0,6">
-                                    <Button DockPanel.Dock="Right" Content="..." Width="24" Height="24"
-                                            Click="WebcamBorderColorPicker_Click" Margin="4,0,0,0"
-                                            ToolTip="Pick color"/>
-                                    <TextBox Text="{Binding SelectedElement.BorderColor, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"
-                                             MaxLength="7" ToolTip="#RRGGBB"/>
-                                </DockPanel>
-                                <TextBlock Text="Border Thickness" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
-                                <DockPanel Margin="0,0,0,6">
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" Margin="4,0,0,0"
-                                            Click="WebcamBorderAccept_Click">
-                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" ToolTip="Revert"
-                                            Click="WebcamBorderRevert_Click" Margin="4,0,0,0">
-                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <Slider DockPanel.Dock="Left" Width="120" Minimum="0" Maximum="10"
-                                            Value="{Binding SelectedElement.BorderWidth, Mode=TwoWay}"
-                                            VerticalAlignment="Center" TickFrequency="1" IsSnapToTickEnabled="True"/>
-                                    <TextBlock Text="{Binding SelectedElement.BorderWidth}" Foreground="#a0a0b0" FontSize="11"
-                                               VerticalAlignment="Center" Margin="8,0,0,0" Width="20"/>
-                                </DockPanel>
-                            </StackPanel>
-
-                            <!-- Countdown config -->
-                            <StackPanel Visibility="{Binding SelectedElement.IsCountdown, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
-                                <TextBlock Text="Timer (minutes)" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
-                                <DockPanel Margin="0,0,0,6">
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" Margin="4,0,0,0"
-                                            Click="CountdownAccept_Click">
-                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" ToolTip="Revert"
-                                            Click="CountdownRevert_Click" Margin="4,0,0,0">
-                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <Slider DockPanel.Dock="Left" Width="120" Minimum="1" Maximum="60"
-                                            Value="{Binding SelectedElement.TimerMinutes, Mode=TwoWay}"
-                                            VerticalAlignment="Center" TickFrequency="1" IsSnapToTickEnabled="True"/>
-                                    <TextBlock Text="{Binding SelectedElement.TimerMinutes}" Foreground="#a0a0b0" FontSize="11"
-                                               VerticalAlignment="Center" Margin="8,0,0,0" Width="20"/>
-                                </DockPanel>
-                            </StackPanel>
-
-                            <!-- Web source config -->
-                            <StackPanel Visibility="{Binding SelectedElement.IsWebSource, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
-                                <TextBlock Text="Geometry" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold" Margin="0,0,0,4"/>
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="X" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="16"/>
-                                    <TextBox Text="{Binding SelectedElement.X, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
-                                    <TextBlock DockPanel.Dock="Left" Text="  Y" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="20" Margin="8,0,0,0"/>
-                                    <TextBox Text="{Binding SelectedElement.Y, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
-                                </DockPanel>
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="W" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="16"/>
-                                    <TextBox Text="{Binding SelectedElement.Width, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
-                                    <TextBlock DockPanel.Dock="Left" Text="  H" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="20" Margin="8,0,0,0"/>
-                                    <TextBox Text="{Binding SelectedElement.Height, UpdateSourceTrigger=PropertyChanged, StringFormat=F0}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"/>
-                                </DockPanel>
-                                <TextBlock Text="URI" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"/>
-                                <DockPanel>
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" Margin="4,0,0,0" IsTabStop="False"
-                                            Click="WebAccept_Click">
-                                        <Path Data="M4,9 L8,14 L16,4" Stroke="#22c55e" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <Button DockPanel.Dock="Right" Style="{StaticResource IconButton}"
-                                            Width="22" Height="22" ToolTip="Revert" IsTabStop="False"
-                                            Click="WebRevert_Click" Margin="4,0,0,0">
-                                        <Path Data="M5,5 L15,15 M15,5 L5,15" Stroke="#e94560" StrokeThickness="2"
-                                              Width="14" Height="14" Stretch="Uniform"/>
-                                    </Button>
-                                    <TextBox Text="{Binding SelectedElement.WebUri, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0d0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="12"
-                                             ToolTip="https://example.com"/>
-                                </DockPanel>
-                            </StackPanel>
-
-                            <!-- Chat box config -->
-                            <StackPanel Visibility="{Binding SelectedElement.IsChatBox, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
-                                <TextBlock Text="Chat Overlay" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold" Margin="0,0,0,6"/>
-
-                                <!-- Font Size -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Font Size" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <Slider x:Name="ChatFontSizeSlider" Width="120" Minimum="8" Maximum="72" TickFrequency="2" IsSnapToTickEnabled="True"
-                                            Value="{Binding SelectedElement.ChatFontSize, Mode=TwoWay}"
-                                            VerticalAlignment="Center"/>
-                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatFontSize, StringFormat={}{0:0}}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
-                                </DockPanel>
-
-                                <!-- Font Family -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Font" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <ComboBox SelectedValue="{Binding SelectedElement.ChatFontFamily, Mode=TwoWay}"
-                                              SelectedValuePath="Content"
-                                              Background="#0f3460" Foreground="#e0e0e0" FontSize="11"
-                                              Width="140" VerticalAlignment="Center">
-                                        <ComboBoxItem Content="Segoe UI"/>
-                                        <ComboBoxItem Content="Arial"/>
-                                        <ComboBoxItem Content="Consolas"/>
-                                        <ComboBoxItem Content="Courier New"/>
-                                        <ComboBoxItem Content="Comic Sans MS"/>
-                                        <ComboBoxItem Content="Mouse Memoirs"/>
-                                    </ComboBox>
-                                </DockPanel>
-
-                                <!-- Font Color -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Font Color" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <TextBox Text="{Binding SelectedElement.ChatFontColor, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
-                                </DockPanel>
-
-                                <!-- Member Color -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Member" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <TextBox Text="{Binding SelectedElement.ChatMemberColor, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
-                                </DockPanel>
-
-                                <!-- Super Chat Color -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Super Chat" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <TextBox Text="{Binding SelectedElement.ChatSuperChatColor, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
-                                </DockPanel>
-
-                                <!-- Max Messages -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Max Msgs" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <Slider x:Name="ChatMaxMsgsSlider" Width="120" Minimum="1" Maximum="20" TickFrequency="1" IsSnapToTickEnabled="True"
-                                            Value="{Binding SelectedElement.ChatMaxMessages, Mode=TwoWay}"
-                                            VerticalAlignment="Center"/>
-                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatMaxMessages}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
-                                </DockPanel>
-
-                                <!-- Background Color -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Background" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <TextBox Text="{Binding SelectedElement.ChatBackgroundColor, UpdateSourceTrigger=PropertyChanged}"
-                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
-                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
-                                </DockPanel>
-
-                                <!-- Background Opacity -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Bg Opacity" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <Slider x:Name="ChatBgOpacitySlider" Width="120" Minimum="0" Maximum="1"
-                                            Value="{Binding SelectedElement.ChatBackgroundOpacity, Mode=TwoWay}"
-                                            VerticalAlignment="Center"/>
-                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatBackgroundOpacity, StringFormat={}{0:0%}}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="32"/>
-                                </DockPanel>
-
-                                <!-- Fade After (seconds) -->
-                                <DockPanel Margin="0,0,0,4">
-                                    <TextBlock DockPanel.Dock="Left" Text="Fade After" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
-                                    <Slider x:Name="ChatFadeSlider" Width="120" Minimum="0" Maximum="60" TickFrequency="5" IsSnapToTickEnabled="True"
-                                            Value="{Binding SelectedElement.ChatFadeSeconds, Mode=TwoWay}"
-                                            VerticalAlignment="Center"/>
-                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatFadeSeconds, StringFormat='{}{0}s'}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="28"/>
-                                </DockPanel>
-
-                                <!-- Toggles -->
-                                <CheckBox Content="Show timestamps" Foreground="#a0a0b0" FontSize="11" Margin="0,4,0,2"
-                                          IsChecked="{Binding SelectedElement.ChatShowTimestamps, Mode=TwoWay}"/>
-                                <CheckBox Content="Show badges" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"
-                                          IsChecked="{Binding SelectedElement.ChatShowBadges, Mode=TwoWay}"/>
-                            </StackPanel>
-
-                            <!-- Background properties -->
-                            <StackPanel Margin="0,8,0,0"
-                                        Visibility="{Binding SelectedElement.IsBackground, Converter={StaticResource BoolToVis}}">
-                                <TextBlock Text="Background" Style="{StaticResource SubHeader}"/>
-                                <StackPanel Margin="4,0,0,0">
-                                    <StackPanel Orientation="Horizontal" Margin="0,0,0,8">
-                                        <TextBlock Text="Use default background:" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center"/>
-                                        <ToggleButton Style="{StaticResource PillToggle}"
-                                                      IsChecked="{Binding SelectedElement.UseDefaultBackground, Mode=TwoWay}"
-                                                      Margin="8,0,0,0"/>
-                                    </StackPanel>
-                                    <Grid Margin="0,0,0,4"
-                                          Visibility="{Binding SelectedElement.UseDefaultBackground, Converter={StaticResource InverseBoolToVis}}">
-                                        <Grid.ColumnDefinitions>
-                                            <ColumnDefinition Width="*"/>
-                                            <ColumnDefinition Width="Auto"/>
-                                        </Grid.ColumnDefinitions>
-                                        <TextBox Grid.Column="0" Text="{Binding SelectedElement.CustomBackgroundPath, Mode=OneWay}"
-                                                  IsReadOnly="True" Background="#0f3460" Foreground="#a0a0b0"
-                                                  FontSize="11" VerticalAlignment="Center"/>
-                                        <Button Grid.Column="1" Content="Browse…" Command="{Binding BrowseBackgroundCommand}"
-                                                Style="{StaticResource YtButtonSecondary}" Margin="4,0,0,0" Padding="8,2"/>
-                                    </Grid>
-                                    <TextBlock Text="{Binding BackgroundSizeMismatchText}"
-                                               Foreground="#ef4444" FontSize="11" TextWrapping="Wrap"
-                                               Margin="0,4,0,0"
-                                               Visibility="{Binding BackgroundSizeMismatch, Converter={StaticResource BoolToVis}}"/>
-                                </StackPanel>
-                            </StackPanel>
-                        </StackPanel>
-                    </ScrollViewer>
-                </Grid>
-
-                <!-- Live mode: YouTube Live Chat (entire left panel replaced) -->
-                <Grid Grid.Row="0" Visibility="{Binding IsEditMode, Converter={StaticResource InverseBoolToVis}}">
-                    <Grid.RowDefinitions>
-                        <RowDefinition Height="Auto"/>
-                        <RowDefinition Height="*"/>
-                    </Grid.RowDefinitions>
-
-                    <TextBlock Grid.Row="0" Text="LIVE CHAT" Style="{StaticResource SectionHeader}"/>
-
-                    <!-- Inactive overlay (shown when NOT live) -->
-                    <StackPanel Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Center"
-                                Visibility="{Binding ShowChatInactiveMessage, Converter={StaticResource BoolToVis}}">
-                        <TextBlock Text="Chat is inactive" Foreground="#a0a0b0" FontSize="13"
-                                   HorizontalAlignment="Center" Margin="0,0,0,4"/>
-                        <TextBlock Text="Chat becomes active once LlamaCasty is connected and streaming on YouTube."
-                                   Foreground="#666" FontSize="11" TextWrapping="Wrap"
-                                   HorizontalAlignment="Center" TextAlignment="Center" MaxWidth="240"/>
-                    </StackPanel>
-
-                    <!-- Message feed (shown when live) -->
-                    <ListBox Grid.Row="1" Background="Transparent" BorderThickness="0"
-                             ItemsSource="{Binding ChatMessages}"
-                             ItemContainerStyle="{StaticResource YtListBoxItem}"
-                             Visibility="{Binding ShowChatInactiveMessage, Converter={StaticResource InverseBoolToVis}}"
-                             x:Name="ChatListBox">
-                        <ListBox.ItemTemplate><DataTemplate>
-                            <Border x:Name="MessageBorder" Padding="6,4" CornerRadius="4">
-                                <Border.Style>
-                                    <Style TargetType="Border">
-                                        <Setter Property="Background" Value="Transparent"/>
-                                        <Style.Triggers>
-                                            <DataTrigger Binding="{Binding IsSuperChat}" Value="True">
-                                                <Setter Property="Background" Value="#2a1a0a"/>
-                                                <Setter Property="BorderBrush" Value="#eab308"/>
-                                                <Setter Property="BorderThickness" Value="1,0,1,0"/>
-                                            </DataTrigger>
-                                        </Style.Triggers>
-                                    </Style>
-                                </Border.Style>
-                                <StackPanel>
-                                    <StackPanel Orientation="Horizontal" Margin="0,0,0,2">
-                                        <TextBlock Text="&#x2B50;" FontSize="10" Margin="0,0,4,0"
-                                                   VerticalAlignment="Center"
-                                                   Visibility="{Binding IsMember, Converter={StaticResource BoolToVis}}"/>
-                                        <TextBlock Text="{Binding AuthorName}" Foreground="#e94560"
-                                                   FontWeight="Bold" FontSize="12" VerticalAlignment="Center"/>
-                                        <TextBlock Text="{Binding SuperChatAmount, StringFormat=${0:F2}}"
-                                                   Foreground="#eab308" FontWeight="Bold" FontSize="12"
-                                                   Margin="8,0,0,0" VerticalAlignment="Center"
-                                                   Visibility="{Binding IsSuperChat, Converter={StaticResource BoolToVis}}"/>
-                                        <TextBlock Text="{Binding SuperChatCurrency}" Foreground="#eab308"
-                                                   FontSize="11" Margin="2,0,0,0" VerticalAlignment="Center"
-                                                   Visibility="{Binding IsSuperChat, Converter={StaticResource BoolToVis}}"/>
-                                    </StackPanel>
-                                    <TextBlock Text="{Binding Message}" Foreground="#e0e0e0"
-                                               TextWrapping="Wrap" Margin="0,2,0,0"/>
-                                </StackPanel>
-                            </Border>
-                        </DataTemplate></ListBox.ItemTemplate>
-                    </ListBox>
-                </Grid>
-            </Grid>
-            </Border>
 
             <!-- CENTER: Preview Area -->
             <controls:PreviewPane x:Name="PreviewPane" Grid.Row="1" Grid.Column="1"/>
@@ -599,173 +108,7 @@
 
         <controls:BottomBar Grid.Row="3"/>
         <!-- ═══ OVERLAY: Settings / Bug / Feature / About ═══ -->
-        <Grid Grid.RowSpan="3"
-              Visibility="{Binding IsAnyOverlayOpen, Converter={StaticResource BoolToVis}}">
-            <Button Background="#99000000" BorderThickness="0" Cursor="Hand"
-                    Command="{Binding CloseOverlayCommand}">
-                <Button.Template>
-                    <ControlTemplate TargetType="Button">
-                        <Border Background="{TemplateBinding Background}"/>
-                    </ControlTemplate>
-                </Button.Template>
-            </Button>
-
-            <Border Background="#0A0C1A" CornerRadius="8" Width="650" MaxHeight="700"
-                    VerticalAlignment="Center" HorizontalAlignment="Center"
-                    Padding="28" BorderBrush="#333" BorderThickness="1">
-                <Grid>
-                    <Grid.RowDefinitions>
-                        <RowDefinition Height="Auto"/>
-                        <RowDefinition Height="Auto"/>
-                    </Grid.RowDefinitions>
-
-                    <!-- Header -->
-                    <Grid Grid.Row="0">
-                        <TextBlock Text="{Binding OverlayTitle}" FontSize="18" FontWeight="Bold"
-                                   Foreground="#e0e0e0" VerticalAlignment="Center"/>
-                        <Button HorizontalAlignment="Right" ToolTip="Close" Style="{StaticResource IconButton}"
-                                Command="{Binding CloseOverlayCommand}">
-                            <Path Data="M19,6.41L17.59,5 12,10.59 6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 12,13.41 17.59,19 19,17.59 13.41,12z"
-                                  Fill="#d0d0d0" Width="14" Height="14" Stretch="Uniform"/>
-                        </Button>
-                    </Grid>
-
-                    <!-- App Settings: broadcast fields live in the preview's
-                         Text pull-out now — this panel keeps app-level prefs only.
-                         (Currently empty; the overlay shell stays for future use.) -->
-                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
-                                Visibility="{Binding IsSettingsOpen, Converter={StaticResource BoolToVis}}">
-                        <TextBlock Text="Default Location for Recordings" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                        <TextBox Style="{StaticResource YtTextBox}" 
-                                 Text="{Binding RecordFolderDisplay, Mode=OneWay}"
-                                 IsReadOnly="True" Margin="0,0,0,12" Foreground="#a0a0b0"/>
-                        <StackPanel Orientation="Horizontal">
-                            <Button Content="Browse…" Command="{Binding ChooseRecordFolderCommand}"
-                                    Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
-                            <Button Content="Use Downloads" Command="{Binding ResetRecordFolderCommand}"
-                                    Style="{StaticResource YtButtonSecondary}"/>
-                        </StackPanel>
-                    </StackPanel>
-
-                    <!-- Report Bug -->
-                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
-                                Visibility="{Binding IsBugOpen, Converter={StaticResource BoolToVis}}">
-                        <TextBlock Text="What went wrong?" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                        <TextBox Style="{StaticResource YtTextBox}" Height="110" AcceptsReturn="True" TextWrapping="Wrap"
-                                 Margin="0,0,0,12"
-                                 Text="{Binding BugReportText, UpdateSourceTrigger=PropertyChanged}"
-                                 VerticalScrollBarVisibility="Auto"/>
-
-                        <TextBlock Text="Email (optional)" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                        <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
-                                 Text="{Binding BugReportEmail, UpdateSourceTrigger=PropertyChanged}"/>
-
-                        <TextBlock Text="Opens a pre-filled email to the LlamaCasty team." Style="{StaticResource YtLabel}"/>
-                        <Button Content="Send Report" Command="{Binding SubmitBugCommand}"
-                                Style="{StaticResource YtButton}" HorizontalAlignment="Right" Margin="0,16,0,0"/>
-                    </StackPanel>
-
-                    <!-- Feature Request -->
-                    <StackPanel Grid.Row="1" Margin="0,16,0,0"
-                                Visibility="{Binding IsFeatureOpen, Converter={StaticResource BoolToVis}}">
-                        <TextBlock Text="What would you like to see?" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                        <TextBox Style="{StaticResource YtTextBox}" Height="110" AcceptsReturn="True" TextWrapping="Wrap"
-                                 Margin="0,0,0,12"
-                                 Text="{Binding FeatureRequestText, UpdateSourceTrigger=PropertyChanged}"
-                                 VerticalScrollBarVisibility="Auto"/>
-
-                        <TextBlock Text="Email (optional)" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                        <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
-                                 Text="{Binding FeatureRequestEmail, UpdateSourceTrigger=PropertyChanged}"/>
-
-                        <TextBlock Text="Opens a pre-filled email to the LlamaCasty team." Style="{StaticResource YtLabel}"/>
-                        <Button Content="Send Request" Command="{Binding SubmitFeatureCommand}"
-                                Style="{StaticResource YtButton}" HorizontalAlignment="Right" Margin="0,16,0,0"/>
-                    </StackPanel>
-
-                    <!-- About -->
-                    <Grid Grid.Row="1" Margin="0,16,0,0"
-                          Background="#171928"
-                          Visibility="{Binding IsAboutOpen, Converter={StaticResource BoolToVis}}">
-
-                        <!-- Hub view -->
-                        <StackPanel Visibility="{Binding IsHubVisible, Converter={StaticResource BoolToVis}}">
-                            <Image Source="/ytLive;component/Assets/llamacasty-logo.jpg" Height="125" Stretch="Uniform"
-                                   HorizontalAlignment="Center" Margin="0,0,0,12"/>
-                            <TextBlock Text="{Binding AppVersionLabel}" Foreground="#a0a0b0" FontSize="12"
-                                       HorizontalAlignment="Center" Margin="0,4,0,0"/>
-                            <TextBlock Text="Live streaming for YouTube — simple enough that even the most right-brained person can intuit it."
-                                       Foreground="#a0a0b0" FontSize="13" TextWrapping="Wrap" MaxWidth="380"
-                                       TextAlignment="Center" Margin="0,16,0,0"/>
-                            <TextBlock Text="Free forever — live streams carry a brief &quot;made with LlamaCasty!&quot; flash. A subscription removes it and adds alerts."
-                                       Foreground="#888" FontSize="12" TextWrapping="Wrap" MaxWidth="380"
-                                       TextAlignment="Center" Margin="0,12,0,0"/>
-                            <TextBlock Text="Made by gramps · llama chile shop" Foreground="#a0a0b0" FontSize="12"
-                                       HorizontalAlignment="Center" Margin="0,16,0,8"/>
-
-                            <!-- Creator hub links -->
-                            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,0,0,8">
-                                <Button Content="llama chile shop on YouTube" Command="{Binding OpenChannelCommand}"
-                                        Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
-                                <Button Content="Mastodon" Command="{Binding OpenMastodonCommand}"
-                                        Style="{StaticResource YtButtonSecondary}"/>
-                            </StackPanel>
-                            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
-                                <Button Content="Buy me a coffee" Command="{Binding OpenCoffeeCommand}"
-                                        Style="{StaticResource YtButtonSecondary}" Margin="0,0,8,0"/>
-                                <Button Content="Unlock Premium" Command="{Binding OpenPremiumCommand}"
-                                        Style="{StaticResource YtButtonSecondary}"
-                                        IsEnabled="{Binding IsPremiumAvailable}"
-                                        ToolTip="Open the LlamaCasty subscription page"/>
-                                <Button Content="Enter License Key" Command="{Binding OpenLicenseEntryCommand}"
-                                        Style="{StaticResource YtButtonSecondary}"
-                                        ToolTip="Activate a license key to remove the watermark"/>
-                            </StackPanel>
-
-                            <Button Content="Licenses &amp; legal" Command="{Binding OpenLicensesCommand}"
-                                    Style="{StaticResource YtButtonSecondary}" HorizontalAlignment="Center"
-                                    Margin="0,16,0,0"/>
-                        </StackPanel>
-
-                        <!-- Licensing/legal panel -->
-                        <StackPanel Visibility="{Binding IsLicensesOpen, Converter={StaticResource BoolToVis}}">
-                            <TextBlock Text="Third-party notices &amp; license texts" FontSize="15" FontWeight="Bold"
-                                       Foreground="#e0e0e0" Margin="0,0,0,8"/>
-                            <Border Background="#10101e" CornerRadius="4" Padding="10" MaxHeight="360"
-                                    BorderBrush="#333" BorderThickness="1">
-                                <ScrollViewer VerticalScrollBarVisibility="Auto">
-                                    <TextBlock Text="{Binding LicensesText}" Foreground="#b8b8c8" FontSize="11"
-                                               FontFamily="Consolas" TextWrapping="Wrap"/>
-                                </ScrollViewer>
-                            </Border>
-                            <Button Content="← Back to About" Style="{StaticResource YtButtonSecondary}"
-                                    HorizontalAlignment="Left" Margin="0,12,0,0"
-                                    Click="BackToAbout_Click"/>
-                        </StackPanel>
-
-                        <!-- License key entry panel -->
-                        <StackPanel Visibility="{Binding IsLicenseEntryOpen, Converter={StaticResource BoolToVis}}">
-                            <TextBlock Text="Activate LlamaCasty Premium" FontSize="15" FontWeight="Bold"
-                                       Foreground="#e0e0e0" Margin="0,0,0,8"/>
-                            <TextBlock Text="Enter your license key to remove the branding watermark."
-                                       Foreground="#a0a0b0" FontSize="12" TextWrapping="Wrap" Margin="0,0,0,12"/>
-                            <TextBlock Text="License Key" Style="{StaticResource YtLabel}" Margin="0,0,0,4"/>
-                            <TextBox Style="{StaticResource YtTextBox}" Margin="0,0,0,12"
-                                     Text="{Binding LicenseKey, UpdateSourceTrigger=PropertyChanged}"
-                                     MaxLength="100"/>
-                            <Button Content="Activate" Command="{Binding ActivateLicenseCommand}"
-                                    Style="{StaticResource YtButton}" HorizontalAlignment="Right"
-                                    Margin="0,0,0,8"/>
-                            <TextBlock Text="{Binding LicenseMessage}" Foreground="#a0a0b0" FontSize="12"
-                                       TextWrapping="Wrap" Margin="0,0,0,8"/>
-                            <Button Content="← Back to About" Style="{StaticResource YtButtonSecondary}"
-                                    HorizontalAlignment="Left" Margin="0,8,0,0"
-                                    Click="BackToAbout_Click"/>
-                        </StackPanel>
-                    </Grid>
-                </Grid>
-            </Border>
-        </Grid>
+        <controls:OverlayHost Grid.RowSpan="3"/>
 
         <!-- ═══ WEB SOURCE HOST: hidden panel for WebView2 controls ═══ -->
         <Canvas x:Name="WebViewHostPanel" Grid.RowSpan="4"

MainWindow.xaml.cs

@@ -1,12 +1,10 @@
 using System;
-using System.Collections;
 using System.ComponentModel;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Media;
 using ytLive.Helpers;
-using ytLive.Models;
 using ytLive.ViewModels;
 
 namespace ytLive;
@@ -16,6 +14,7 @@ public partial class MainWindow : Window
     private readonly MainViewModel _viewModel;
     private Controls.TopBar _topBar = null!;
     private Controls.PreviewPane _previewPane = null!;
+    private Controls.LeftPanel _leftPanel = null!;
 
     public MainWindow()
     {
@@ -25,9 +24,9 @@ public partial class MainWindow : Window
         _viewModel = (MainViewModel)DataContext;
         _viewModel.InitWebView2(WebViewHostPanel);
         _viewModel.PropertyChanged += OnViewModelPropertyChanged;
-        _viewModel.ChatMessages.CollectionChanged += OnChatMessagesChanged;
         _topBar = (Controls.TopBar)FindName("TopBar")!;
         _previewPane = (Controls.PreviewPane)FindName("PreviewPane")!;
+        _leftPanel = (Controls.LeftPanel)FindName("LeftPanel")!;
         UpdateTaskbarOverlay();
         UpdateSelectionOverlay();
         _topBar.RefreshAvatar();
@@ -136,35 +135,6 @@ public partial class MainWindow : Window
             : null;
     }
 
-    private void SourceNameBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
-    {
-        if (sender is TextBox { IsVisible: true } box)
-        {
-            box.Focus();
-            box.SelectAll();
-        }
-    }
-
-    private void BackToAbout_Click(object sender, RoutedEventArgs e)
-    {
-        if (DataContext is ViewModels.MainViewModel vm)
-        {
-            vm.IsLicensesOpen = false;
-            vm.IsLicenseEntryOpen = false;
-        }
-    }
-
-    private void AddSourceButton_Click(object sender, RoutedEventArgs e)
-    {
-        if (sender is Button { ContextMenu: { } menu } button)
-        {
-            menu.PlacementTarget = button;
-            menu.Placement = System.Windows.Controls.Primitives.PlacementMode.Bottom;
-            menu.IsOpen = true;
-        }
-    }
-
-
     private void Window_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
     {
         if (e.OriginalSource is not DependencyObject original) return;
@@ -172,22 +142,10 @@ public partial class MainWindow : Window
         if (form.IsDrawerOpen && !_previewPane.IsClickInsideDrawer(original))
             form.CloseDrawerCommand.Execute(null);
         if (_previewPane.IsClickInsidePreview(original)) return;
-        if (IsDescendantOf(original, SourceList)) return;
-        if (IsDescendantOf(original, ElementsScrollViewer)) return;
+        if (_leftPanel.IsClickInside(original)) return;
         _viewModel.SelectedElement = null;
     }
 
-    private static bool IsDescendantOf(DependencyObject? child, DependencyObject ancestor)
-    {
-        while (child != null && !ReferenceEquals(child, ancestor))
-        {
-            child = child is System.Windows.Media.Visual or System.Windows.Media.Media3D.Visual3D
-                ? VisualTreeHelper.GetParent(child)
-                : LogicalTreeHelper.GetParent(child);
-        }
-        return child != null;
-    }
-
     private void UpdateSelectionOverlay()
     {
         if (!_viewModel.IsEditMode)
@@ -197,249 +155,6 @@ public partial class MainWindow : Window
         }
         var selected = _viewModel.SelectedElement is { } s && Controls.PreviewPane.IsDraggableElement(s);
         _previewPane.UpdateSelectionOverlay(selected);
-        if (selected)
-            OpacityValueText.Text = $"{Math.Round(_viewModel.SelectedElement!.Opacity * 100)}%";
-        TakeSnapshot();
-    }
-
-    private void OnChatMessagesChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
-    {
-        if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
-        {
-            ChatListBox.ScrollIntoView(ChatListBox.Items[^1]);
-        }
-    }
-
-    private void MirrorButton_Click(object sender, RoutedEventArgs e)
-    {
-        if (_viewModel.SelectedElement is WebcamSceneConfig webcam)
-            webcam.IsMirrored = !webcam.IsMirrored;
-    }
-
-    private void ShapeButton_Click(object sender, RoutedEventArgs e)
-    {
-        if (_viewModel.SelectedElement is WebcamSceneConfig webcam)
-            webcam.ToggleClipShape();
-    }
-
-    private void SourceMenu_Remove(object sender, RoutedEventArgs e)
-    {
-        if (sender is MenuItem { DataContext: SceneElement element })
-            _viewModel.RemoveSourceCommand.Execute(element);
-    }
-
-    private void BackgroundMenu_ChangeCapture(object sender, RoutedEventArgs e)
-    {
-        _ = _viewModel.ChangeBackgroundCaptureAsync();
-    }
-
-    private void BackgroundMenu_RefreshCapture(object sender, RoutedEventArgs e)
-    {
-        _viewModel.RefreshBackgroundAutoCapture();
-    }
-
-    private void OpacitySlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
-        => OpacityValueText.Text = $"{Math.Round(e.NewValue * 100)}%";
-
-
-    private void SourceNameBox_KeyDown(object sender, KeyEventArgs e)
-    {
-        if (e.Key is Key.Enter or Key.Escape)
-        {
-            CommitSourceEdit(sender);
-            e.Handled = true;
-        }
-    }
-
-    private void SourceNameBox_LostFocus(object sender, RoutedEventArgs e)
-    {
-        CommitSourceEdit(sender);
-    }
-
-    private static void CommitSourceEdit(object sender)
-    {
-        if (sender is FrameworkElement { DataContext: SceneElement element })
-            element.IsEditing = false;
-    }
-
-    // ─── List drag-to-reorder (scenes list + sources list) ───
-    private Point _dragStartPoint;
-    private int _dragIndex = -1;
-    private bool _isDragging;
-    private object? _lastHoveredItem;
-
-    private void List_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
-    {
-        var listBox = (ListBox)sender;
-        var item = FindItemContainerAt(listBox, e.GetPosition(listBox));
-        if (item == null)
-        {
-            if (ReferenceEquals(listBox, SourceList))
-                _viewModel.SelectedElement = null;
-            _dragIndex = -1;
-            return;
-        }
-        if (listBox.ItemsSource is not IList items || items.Count == 0)
-        {
-            _dragIndex = -1;
-            return;
-        }
-        _dragIndex = listBox.Items.IndexOf(item.DataContext);
-        _dragStartPoint = e.GetPosition(listBox);
-        _isDragging = false;
-        _lastHoveredItem = null;
-    }
-
-    private void List_PreviewMouseMove(object sender, MouseEventArgs e)
-    {
-        if (_dragIndex < 0) return;
-        var listBox = (ListBox)sender;
-        if (e.LeftButton != MouseButtonState.Pressed || listBox.ItemsSource is not IList items)
-        {
-            EndListDrag(listBox);
-            return;
-        }
-
-        var position = e.GetPosition(listBox);
-        if (!_isDragging)
-        {
-            if (Math.Abs(position.X - _dragStartPoint.X) < SystemParameters.MinimumHorizontalDragDistance &&
-                Math.Abs(position.Y - _dragStartPoint.Y) < SystemParameters.MinimumVerticalDragDistance)
-                return;
-            _isDragging = true;
-            listBox.CaptureMouse();
-        }
-
-        var item = FindItemContainerAt(listBox, position);
-        if (item == null) return;
-
-        var targetItem = item.DataContext;
-        if (ReferenceEquals(targetItem, items[_dragIndex]) || ReferenceEquals(targetItem, _lastHoveredItem))
-            return;
-
-        var targetIndex = listBox.Items.IndexOf(targetItem);
-        if (targetIndex < 0) return;
-
-        var dragged = items[_dragIndex];
-        items.RemoveAt(_dragIndex);
-        items.Insert(targetIndex, dragged);
-        _dragIndex = targetIndex;
-        _lastHoveredItem = targetItem;
-    }
-
-    private void List_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
-    {
-        EndListDrag((ListBox)sender);
-    }
-
-    private void EndListDrag(ListBox listBox)
-    {
-        if (_isDragging)
-            listBox.ReleaseMouseCapture();
-        _dragIndex = -1;
-        _isDragging = false;
-        _lastHoveredItem = null;
-    }
-
-    private static ListBoxItem? FindItemContainerAt(ListBox listBox, Point position)
-    {
-        var hit = listBox.InputHitTest(position) as DependencyObject;
-        while (hit != null && hit != listBox)
-        {
-            if (hit is ListBoxItem item) return item;
-            hit = VisualTreeHelper.GetParent(hit);
-        }
-        return null;
-    }
-
-    private Models.SceneElement? _snapshotElement;
-    private string _snapshotBorderColor = string.Empty;
-    private int _snapshotBorderWidth;
-    private int _snapshotTimerMinutes = 15;
-    private string? _snapshotWebUri;
-
-    private void TakeSnapshot()
-    {
-        if (_viewModel.SelectedElement is Models.Source src)
-        {
-            _snapshotElement = src;
-            _snapshotBorderColor = src.BorderColor;
-            _snapshotBorderWidth = src.BorderWidth;
-            _snapshotTimerMinutes = src.TimerMinutes;
-            _snapshotWebUri = src.WebUri;
-        }
-    }
-
-    private void WebcamBorderColorPicker_Click(object sender, RoutedEventArgs e)
-    {
-        if (_viewModel.SelectedElement is not SceneElement src) return;
-        if (sender is FrameworkElement fe && fe.ContextMenu == null)
-        {
-            var menu = new System.Windows.Controls.ContextMenu();
-            string[] colors = ["#FFFFFF", "#000000", "#FF0000", "#00FF00", "#0000FF",
-                               "#FFFF00", "#FF00FF", "#00FFFF", "#FF8800", "#8800FF",
-                               "#e94560", "#22c55e", "#3b82f6", "#f59e0b"];
-            foreach (var c in colors)
-            {
-                var item = new System.Windows.Controls.MenuItem { Header = c, ToolTip = c };
-                var brush = new System.Windows.Media.SolidColorBrush(
-                    (System.Windows.Media.Color)System.Windows.Media.ColorConverter.ConvertFromString(c));
-                item.Icon = new System.Windows.Controls.Border
-                {
-                    Width = 16, Height = 16,
-                    Background = brush,
-                    CornerRadius = new System.Windows.CornerRadius(2)
-                };
-                var color = c;
-                item.Click += (_, _) => src.BorderColor = color;
-                menu.Items.Add(item);
-            }
-            fe.ContextMenu = menu;
-        }
-        if (sender is FrameworkElement fe2)
-            fe2.ContextMenu.IsOpen = true;
-    }
-
-    private void WebcamBorderRevert_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-        {
-            src.BorderColor = _snapshotBorderColor;
-            src.BorderWidth = _snapshotBorderWidth;
-        }
-    }
-
-    private void WebcamBorderAccept_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-        {
-            _snapshotBorderColor = src.BorderColor;
-            _snapshotBorderWidth = src.BorderWidth;
-        }
-    }
-
-    private void CountdownRevert_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-            src.TimerMinutes = _snapshotTimerMinutes;
-    }
-
-    private void CountdownAccept_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-            _snapshotTimerMinutes = src.TimerMinutes;
-    }
-
-    private void WebRevert_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-            src.WebUri = string.Empty;
-        _snapshotWebUri = string.Empty;
-    }
-
-    private void WebAccept_Click(object sender, RoutedEventArgs e)
-    {
-        if (_snapshotElement is Models.Source src)
-            _snapshotWebUri = src.WebUri;
+        _leftPanel.OnSelectionChanged(_viewModel);
     }
 }

MyMistakes.md

@@ -44,3 +44,26 @@ packages, high-quality downscale via `TransformedBitmap`. Screenshots compress
 4. Point `README.md` at the `.jpg` (not `.png`).
 
 **Result:** 3.2MB screenshot → 1400×794 → **188KB** `ytLlive-preview.jpg` in `docs/`.
+
+---
+
+## Splitting a large file into partials — NEVER `awk … > SRC` while awking SRC
+
+(2026-08-31, Commit D) Tried to split `SocialsDialogViewModel.cs` in one line:
+`{ awk '…' SRC; echo ""; awk '…2…' SRC; } > SRC`. The **first write truncated
+SRC to 1 line**, so the second `awk` read the already-truncated file → the whole
+source was lost (1 line left). Recovered with `git checkout -- SRC`, then redid
+it, but the same bug could have meant making it up from scratch.
+
+**Rule:** when a cut needs N blocks from one source into N files, never write a
+block back onto the source that the `awk`s still read. Instead:
+1. Read the source **once** at the start into temp files (`mktemp -d`, one file
+   per block), with a `$D` variable you carry forward.
+2. Verify block sizes (`wc -l`) and brace balance (`python3 -c` counting `{`/`}`)
+   before touching any real file.
+3. Then assemble each new file from `cat D/block …` — never truncating the source
+   until every read is done.
+
+`git status` can't save you here if you don't notice until the file is gone —
+`git checkout -- <path>` from the last commit is the recovery. Cheap insurance:
+restore-then-retry, do it atomically from temp files the first time.

Services/ChatOverlayLayer.cs

@@ -0,0 +1,199 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Windows;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Threading;
+using ytLive.Helpers;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+/// <summary>Owns the YouTube-chat overlay behavior: the message buffer, the
+/// renderer, and the fade/mock-preview timers. The MainViewModel keeps only the
+/// thin binding surface (the shared <see cref="Messages"/> collection + two
+/// computed gate props) and hands the scene list in at each call — this class
+/// owns all chat logic so an AI can read one self-contained unit.</summary>
+public sealed class ChatOverlayLayer
+{
+    private readonly ChatBoxRenderer _renderer;
+
+    // Mock chat messages for the ChatBox preview — branded placeholders so the
+    // creator sees where the overlay lands before going live.
+    private static readonly IReadOnlyList<ChatMessage> MockChatMessages = new[]
+    {
+        new ChatMessage { AuthorName = "LlamaCasty", Message = "welcome to the stream!", Timestamp = DateTime.Now.AddMinutes(-4), IsMember = true },
+        new ChatMessage { AuthorName = "LlamaCastyFan", Message = "$10 — LlamaCasty is the best!", Timestamp = DateTime.Now.AddMinutes(-3), IsSuperChat = true },
+        new ChatMessage { AuthorName = "GamerDude", Message = "what streaming software is this?", Timestamp = DateTime.Now.AddMinutes(-2) },
+        new ChatMessage { AuthorName = "LlamaCasty", Message = "thanks for watching! llamacasty.com", Timestamp = DateTime.Now.AddMinutes(-1), IsMember = true },
+        new ChatMessage { AuthorName = "LlamaDog", Message = "Subscribe so they can buy the subscription at llamacasty.com!", Timestamp = DateTime.Now, IsMember = true },
+    };
+
+    // Chat fade timer: clears chat overlay after N seconds of inactivity.
+    private DispatcherTimer? _fadeTimer;
+    private CancellationTokenSource? _mockCts;
+
+    /// <summary>The live chat message buffer. Shared with the ViewModel (which
+    /// binds it to the panel) via <c>ChatMessages =&gt; _chatLayer.Messages</c>.</summary>
+    public ObservableCollection<ChatMessage> Messages { get; } = new();
+
+    public ChatOverlayLayer(ChatBoxRenderer renderer) => _renderer = renderer;
+
+    /// <summary>Ingest a message from the poller. UI-thread marshalled: appended
+    /// to the buffer (capped at 500), mock preview stopped, swipe to real
+    /// messages, and the fade timer reset. Scenes are handed in so the layer can
+    /// refresh every ChatBox preview without owning the scene graph.</summary>
+    public void OnMessageReceived(ChatMessage message, IEnumerable<Scene> scenes)
+    {
+        System.Windows.Application.Current.Dispatcher.Invoke(() =>
+        {
+            Messages.Add(message);
+            if (Messages.Count > 500)
+                Messages.RemoveAt(0);
+
+            // Reset chat fade timer on every message
+            ResetChatFadeTimer(scenes);
+
+            StopMockPreview();
+
+            // Switch ChatBox previews from mock to real messages
+            foreach (var chatBox in scenes.SelectMany(s => s.Elements).OfType<Source>()
+                         .Where(s => s.Type == SourceType.ChatBox))
+                UpdatePreview(chatBox);
+        });
+    }
+
+    private void ResetChatFadeTimer(IEnumerable<Scene> scenes)
+    {
+        _fadeTimer?.Stop();
+        var chatBoxes = scenes.SelectMany(s => s.Elements).OfType<Source>()
+            .Where(s => s.Type == SourceType.ChatBox && s.ChatFadeSeconds > 0).ToList();
+        if (chatBoxes.Count == 0) return;
+
+        var delay = chatBoxes.Min(s => s.ChatFadeSeconds);
+        _fadeTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(delay) };
+        _fadeTimer.Tick += (_, _) =>
+        {
+            _fadeTimer?.Stop();
+            _fadeTimer = null;
+            Messages.Clear();
+            foreach (var chatBox in scenes.SelectMany(s => s.Elements).OfType<Source>()
+                         .Where(s => s.Type == SourceType.ChatBox))
+                UpdatePreview(chatBox);
+            StartMockPreview(scenes);
+        };
+        _fadeTimer.Start();
+    }
+
+    /// <summary>Renders the live-output frame for one ChatBox element (the
+    /// compositor path), or null when no messages are buffered yet. Mirrors the
+    /// preview render but without writing onto the source's VideoImageSource.</summary>
+    public VideoFrame? RenderFrame(Source chatBox)
+    {
+        if (Messages.Count == 0) return null;
+
+        var width = (int)Math.Max(1, chatBox.Width);
+        var height = (int)Math.Max(1, chatBox.Height);
+
+        return _renderer.Render(
+            Messages,
+            width,
+            height,
+            chatBox.ChatFontSize,
+            chatBox.ChatFontFamily,
+            chatBox.ChatFontColor,
+            chatBox.ChatBackgroundColor,
+            chatBox.ChatMaxMessages,
+            chatBox.ChatShowTimestamps,
+            chatBox.ChatShowBadges,
+            chatBox.ChatMemberColor,
+            chatBox.ChatSuperChatColor);
+    }
+
+    /// <summary>Renders one ChatBox preview: real messages when connected, mock
+    /// when not. Writes the resulting bitmap onto the source's
+    /// <c>VideoImageSource</c>.</summary>
+    public void UpdatePreview(Source chatBox, IReadOnlyList<ChatMessage>? messages = null)
+    {
+        try
+        {
+            messages ??= Messages.Count > 0 ? (IReadOnlyList<ChatMessage>)Messages : MockChatMessages;
+            var width = (int)Math.Max(32, chatBox.Width);
+            var height = (int)Math.Max(32, chatBox.Height);
+
+            var frame = _renderer.Render(
+                messages,
+                width,
+                height,
+                chatBox.ChatFontSize,
+                chatBox.ChatFontFamily,
+                chatBox.ChatFontColor,
+                chatBox.ChatBackgroundColor,
+                chatBox.ChatMaxMessages,
+                chatBox.ChatShowTimestamps,
+                chatBox.ChatShowBadges,
+                chatBox.ChatMemberColor,
+                chatBox.ChatSuperChatColor);
+
+            var bitmap = new WriteableBitmap(width, height, 96, 96, PixelFormats.Bgra32, null);
+            bitmap.WritePixels(new Int32Rect(0, 0, width, height), frame.BgraPixels, frame.Stride, 0);
+            chatBox.VideoImageSource = bitmap;
+        }
+        catch (Exception ex) { AppLog.Write($"UpdateChatBoxPreview failed: {ex.Message}"); }
+    }
+
+    private async Task RunMockPreviewAsync(Source chatBox, CancellationToken ct)
+    {
+        var n = 0;
+        while (!ct.IsCancellationRequested)
+        {
+            UpdatePreview(chatBox, MockChatMessages.Take(n + 1).ToList());
+            await Task.Delay(1000, ct);
+            n++;
+            if (n == MockChatMessages.Count)
+            {
+                await Task.Delay(3000, ct);
+                n = 0;
+            }
+        }
+    }
+
+    public void StartMockPreview(IEnumerable<Scene> scenes)
+    {
+        StopMockPreview();
+        _mockCts = new CancellationTokenSource();
+        var ct = _mockCts.Token;
+        foreach (var chatBox in scenes.SelectMany(s => s.Elements).OfType<Source>()
+                     .Where(s => s.Type == SourceType.ChatBox && s.ChatPreviewEnabled))
+            _ = RunMockPreviewAsync(chatBox, ct);
+    }
+
+    public void StopMockPreview()
+    {
+        _mockCts?.Cancel();
+        _mockCts?.Dispose();
+        _mockCts = null;
+    }
+
+    /// <summary>Render previews + wire property-change subscriptions for all
+    /// ChatBox sources across every scene. Called after layout load so existing
+    /// ChatBox sources show mock content and respond to config changes.</summary>
+    public void UpdateConfiguredBoxes(IEnumerable<Scene> scenes)
+    {
+        foreach (var scene in scenes)
+            foreach (var chatBox in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.ChatBox))
+            {
+                chatBox.PropertyChanged += (_, e) =>
+                {
+                    if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
+                        or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
+                        or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
+                        or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
+                        or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
+                        or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
+                        UpdatePreview(chatBox);
+                };
+                UpdatePreview(chatBox);
+            }
+    }
+}

Services/LayoutStore.Assets.cs

@@ -0,0 +1,41 @@
+using System.Security.Cryptography;
+using Microsoft.Data.Sqlite;
+
+namespace ytLive.Services;
+
+public partial class LayoutStore : IDisposable
+{
+    public byte[]? GetAssetBytes(string assetId)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Data FROM Asset WHERE Id = $id";
+        cmd.Parameters.AddWithValue("$id", assetId);
+        return cmd.ExecuteScalar() as byte[];
+    }
+
+    public string UpsertAsset(byte[] data, int pixelWidth, int pixelHeight)
+    {
+        var hash = Convert.ToHexString(SHA256.HashData(data));
+        var id = Guid.NewGuid().ToString();
+
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = """
+            INSERT INTO Asset (Id, Hash, Data, PixelWidth, PixelHeight)
+            VALUES ($id, $hash, $data, $w, $h)
+            ON CONFLICT(Hash) DO NOTHING;
+            """;
+        cmd.Parameters.AddWithValue("$id", id);
+        cmd.Parameters.AddWithValue("$hash", hash);
+        cmd.Parameters.AddWithValue("$data", data);
+        cmd.Parameters.AddWithValue("$w", pixelWidth);
+        cmd.Parameters.AddWithValue("$h", pixelHeight);
+        cmd.ExecuteNonQuery();
+
+        cmd.CommandText = "SELECT Id FROM Asset WHERE Hash = $hash;";
+        return (string)cmd.ExecuteScalar()!;
+    }
+
+    // ─── License (TASK 10 — Polar billing) ───
+
+    /// <summary>The saved license key, or null if never entered.</summary>
+}

Services/LayoutStore.Load.cs

@@ -0,0 +1,221 @@
+using Microsoft.Data.Sqlite;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+public partial class LayoutStore : IDisposable
+{
+    public List<Scene> Load()
+    {
+        Webcam = null;
+        Socials = null;
+        Music = null;
+        var scenes = new List<Scene>();
+        var sourcesByScene = new Dictionary<string, List<Source>>();
+        var configsByScene = new Dictionary<string, List<WebcamSceneConfig>>();
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "SELECT Id, Name, IsHidden, IsChatScene, HasBackground, HasSocialBar FROM Scene ORDER BY SortOrder";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+            {
+                scenes.Add(new Scene
+                {
+                    Id = reader.GetString(0),
+                    Name = reader.GetString(1),
+                    IsHidden = reader.GetInt32(2) != 0,
+                    IsChatScene = reader.GetInt32(3) != 0,
+                    HasBackground = reader.GetInt32(4) != 0,
+                    HasSocialBar = reader.FieldCount > 5 && !reader.IsDBNull(5) && reader.GetInt32(5) != 0,
+                });
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "SELECT Id, DeviceId, Name FROM Webcam;";
+            using var reader = cmd.ExecuteReader();
+            if (reader.Read())
+            {
+                Webcam = new Webcam
+                {
+                    Id = reader.GetString(0),
+                    DeviceId = reader.GetString(1),
+                    Name = reader.GetString(2),
+                };
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "SELECT Id, BarPosition, BarEnabled FROM Socials LIMIT 1;";
+            using var reader = cmd.ExecuteReader();
+            if (reader.Read())
+            {
+                Socials = new SocialsConfig
+                {
+                    BarPosition = Enum.TryParse<SocialBarPosition>(reader.GetString(1), out var pos) ? pos : SocialBarPosition.Bottom,
+                    BarEnabled = reader.FieldCount > 2 && !reader.IsDBNull(2) && reader.GetInt32(2) != 0,
+                };
+                var socialsId = reader.GetString(0);
+
+                using var entryCmd = _connection.CreateCommand();
+                entryCmd.CommandText = "SELECT Service, Handle, ProfileUrl, Software FROM SocialEntry WHERE SocialsId = $id ORDER BY SortOrder;";
+                entryCmd.Parameters.AddWithValue("$id", socialsId);
+                using var entryReader = entryCmd.ExecuteReader();
+                while (entryReader.Read())
+                {
+                    Socials.Entries.Add(new SocialEntry
+                    {
+                        Service = Enum.TryParse<SocialService>(entryReader.GetString(0), out var svc) ? svc : SocialService.Link,
+                        Handle = entryReader.GetString(1),
+                        ProfileUrl = entryReader.GetString(2),
+                        FediverseSoftware = entryReader.FieldCount > 3 && !entryReader.IsDBNull(3) ? entryReader.GetString(3) : null,
+                    });
+                }
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "SELECT TrackPath, IsEnabled FROM Music LIMIT 1;";
+            using var reader = cmd.ExecuteReader();
+            if (reader.Read())
+            {
+                Music = new Music
+                {
+                    TrackPath = reader.GetString(0),
+                    IsEnabled = reader.GetInt32(1) != 0,
+                };
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = """
+                SELECT Id, SceneId, AssetId, Type, Name, IsEnabled,
+                       X, Y, Width, Height, Opacity, MonitorIndex, ClipShape, IsMirrored,
+                       IsBackground, CaptureKey, ShowDesktop,
+                       ChatFontSize, ChatFontColor, ChatBackgroundColor, ChatMaxMessages,
+                       ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor,
+                       WebUri, MediaPath, MediaIsLooping, MediaVolume, MediaPlaybackState
+                FROM Source ORDER BY SortOrder
+                """;
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+            {
+                var sceneId = reader.GetString(1);
+                var type = Enum.Parse<SourceType>(reader.GetString(3));
+                var source = new Source
+                {
+                    Id = reader.GetString(0),
+                    AssetId = reader.IsDBNull(2) ? null : reader.GetString(2),
+                    Type = type,
+                    Name = reader.GetString(4),
+                    IsEnabled = reader.GetInt32(5) != 0,
+                    X = reader.GetDouble(6),
+                    Y = reader.GetDouble(7),
+                    Width = reader.GetDouble(8),
+                    Height = reader.GetDouble(9),
+                    Opacity = reader.GetDouble(10),
+                    MonitorIndex = reader.IsDBNull(11) ? null : reader.GetInt32(11),
+                    ClipShape = Enum.TryParse<ClipShape>(reader.GetString(12), out var clip) ? clip : ClipShape.Traditional,
+                    IsMirrored = reader.GetInt32(13) != 0,
+                    // Rows saved before the Type setter derived the flag carry
+                    // IsBackground=0; derive from Type, keeping the persisted bit
+                    // for legacy DisplayCapture backdrops.
+                    IsBackground = type == SourceType.Background || reader.GetInt32(14) != 0,
+                    CaptureKey = reader.IsDBNull(15) ? null : reader.GetString(15),
+                    ShowDesktop = reader.GetInt32(16) != 0,
+                    ChatFontSize = reader.IsDBNull(17) ? 16 : reader.GetDouble(17),
+                    ChatFontColor = reader.IsDBNull(18) ? "#FFFFFF" : reader.GetString(18),
+                    ChatBackgroundColor = reader.IsDBNull(19) ? "#80000000" : reader.GetString(19),
+                    ChatMaxMessages = reader.IsDBNull(20) ? 5 : reader.GetInt32(20),
+                    ChatShowTimestamps = reader.IsDBNull(21) ? true : reader.GetInt32(21) != 0,
+                    ChatShowBadges = reader.IsDBNull(22) ? true : reader.GetInt32(22) != 0,
+                    ChatMemberColor = reader.IsDBNull(23) ? "#e94560" : reader.GetString(23),
+                    ChatSuperChatColor = reader.IsDBNull(24) ? "#eab308" : reader.GetString(24),
+                    WebUri = reader.IsDBNull(25) ? null : reader.GetString(25),
+                    MediaPath = reader.IsDBNull(26) ? null : reader.GetString(26),
+                    MediaIsLooping = reader.IsDBNull(27) ? false : reader.GetInt32(27) != 0,
+                    MediaVolume = reader.IsDBNull(28) ? 1.0 : reader.GetDouble(28),
+                    MediaPlaybackState = reader.IsDBNull(29)
+                        ? MediaPlaybackState.Stopped
+                        : Enum.TryParse<MediaPlaybackState>(reader.GetString(29), out var ps)
+                            ? ps
+                            : MediaPlaybackState.Stopped,
+                };
+                if (!sourcesByScene.TryGetValue(sceneId, out var list))
+                    sourcesByScene[sceneId] = list = new List<Source>();
+                list.Add(source);
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = """
+                SELECT SceneId, WebcamId, IsVisible, X, Y, Width, Height, Opacity,
+                       ClipShape, IsMirrored, BorderColor, BorderOpacity, BorderWidth, BorderAnimation,
+                       RectWidth, RectHeight
+                FROM WebcamSceneConfig ORDER BY SortOrder
+                """;
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+            {
+                var sceneId = reader.GetString(0);
+                var config = new WebcamSceneConfig
+                {
+                    WebcamId = reader.GetString(1),
+                    Name = Webcam?.Name ?? "Webcam",
+                    IsVisible = reader.GetInt32(2) != 0,
+                    X = reader.GetDouble(3),
+                    Y = reader.GetDouble(4),
+                    Width = reader.GetDouble(5),
+                    Height = reader.GetDouble(6),
+                    Opacity = reader.GetDouble(7),
+                    ClipShape = Enum.TryParse<ClipShape>(reader.GetString(8), out var clip) ? clip : ClipShape.Traditional,
+                    IsMirrored = reader.GetInt32(9) != 0,
+                    BorderColor = reader.IsDBNull(10) ? string.Empty : reader.GetString(10),
+                    BorderOpacity = reader.IsDBNull(11) ? 1.0 : reader.GetDouble(11),
+                    BorderWidth = reader.IsDBNull(12) ? 0 : reader.GetInt32(12),
+                    BorderAnimation = Enum.TryParse<BorderAnimation>(reader.GetString(13), out var anim) ? anim : BorderAnimation.None,
+                    RectWidth = reader.IsDBNull(14) ? null : reader.GetDouble(14),
+                    RectHeight = reader.IsDBNull(15) ? null : reader.GetDouble(15),
+                };
+                if (!configsByScene.TryGetValue(sceneId, out var list))
+                    configsByScene[sceneId] = list = new List<WebcamSceneConfig>();
+                list.Add(config);
+            }
+        }
+
+        foreach (var scene in scenes)
+        {
+            if (sourcesByScene.TryGetValue(scene.Id, out var sources))
+                foreach (var source in sources)
+                    scene.Elements.Add(source);
+            if (configsByScene.TryGetValue(scene.Id, out var configs))
+                foreach (var config in configs)
+                    scene.Elements.Add(config);
+
+            var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+            if (bg != null)
+            {
+                // Load from source-keyed settings (new) or scene-keyed (legacy migration)
+                var path = GetSetting($"BackgroundPath_{bg.Id}");
+                if (string.IsNullOrWhiteSpace(path))
+                    path = GetSetting($"BackgroundPath_{scene.Id}");
+                if (!string.IsNullOrWhiteSpace(path))
+                    bg.CustomBackgroundPath = path;
+
+                var useDefault = GetSetting($"BackgroundUseDefault_{bg.Id}");
+                if (string.IsNullOrWhiteSpace(useDefault))
+                    useDefault = GetSetting($"BackgroundUseDefault_{scene.Id}");
+                if (useDefault == "0")
+                    bg.UseDefaultBackground = false;
+            }
+        }
+
+        return scenes;
+    }
+}

Services/LayoutStore.Migrations.cs

@@ -0,0 +1,495 @@
+using Microsoft.Data.Sqlite;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+public partial class LayoutStore : IDisposable
+{
+    private void EnsureSchema()
+    {
+        string[] statements =
+        {
+            """
+            CREATE TABLE IF NOT EXISTS Scene (
+                Id TEXT PRIMARY KEY,
+                Name TEXT NOT NULL,
+                IsHidden INTEGER NOT NULL DEFAULT 0,
+                IsChatScene INTEGER NOT NULL DEFAULT 0,
+                HasBackground INTEGER NOT NULL DEFAULT 1,
+                SortOrder INTEGER NOT NULL DEFAULT 0
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Asset (
+                Id TEXT PRIMARY KEY,
+                Hash TEXT NOT NULL UNIQUE,
+                Data BLOB NOT NULL,
+                PixelWidth INTEGER NOT NULL DEFAULT 0,
+                PixelHeight INTEGER NOT NULL DEFAULT 0
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Source (
+                Id TEXT PRIMARY KEY,
+                SceneId TEXT NOT NULL REFERENCES Scene(Id) ON DELETE CASCADE,
+                AssetId TEXT REFERENCES Asset(Id),
+                Type TEXT NOT NULL,
+                Name TEXT NOT NULL,
+                IsEnabled INTEGER NOT NULL DEFAULT 1,
+                X REAL NOT NULL DEFAULT 0,
+                Y REAL NOT NULL DEFAULT 0,
+                Width REAL NOT NULL DEFAULT 0,
+                Height REAL NOT NULL DEFAULT 0,
+                Opacity REAL NOT NULL DEFAULT 1,
+                MonitorIndex INTEGER,
+                DeviceId TEXT,
+                ClipShape TEXT NOT NULL DEFAULT 'Traditional',
+                IsMirrored INTEGER NOT NULL DEFAULT 0,
+                IsBackground INTEGER NOT NULL DEFAULT 0,
+                CaptureKey TEXT,
+                SortOrder INTEGER NOT NULL DEFAULT 0
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Webcam (
+                Id TEXT PRIMARY KEY,
+                DeviceId TEXT NOT NULL UNIQUE,
+                Name TEXT NOT NULL
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS WebcamSceneConfig (
+                SceneId TEXT NOT NULL REFERENCES Scene(Id) ON DELETE CASCADE,
+                WebcamId TEXT NOT NULL REFERENCES Webcam(Id) ON DELETE CASCADE,
+                IsVisible INTEGER NOT NULL DEFAULT 1,
+                X REAL NOT NULL DEFAULT 0,
+                Y REAL NOT NULL DEFAULT 0,
+                Width REAL NOT NULL DEFAULT 0,
+                Height REAL NOT NULL DEFAULT 0,
+                Opacity REAL NOT NULL DEFAULT 1,
+                ClipShape TEXT NOT NULL DEFAULT 'Traditional',
+                IsMirrored INTEGER NOT NULL DEFAULT 0,
+                RectWidth REAL,
+                RectHeight REAL,
+                BorderColor TEXT,
+                BorderOpacity REAL NOT NULL DEFAULT 1,
+                BorderWidth INTEGER NOT NULL DEFAULT 0,
+                BorderAnimation TEXT NOT NULL DEFAULT 'None',
+                SortOrder INTEGER NOT NULL DEFAULT 0,
+                PRIMARY KEY (SceneId, WebcamId)
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Socials (
+                Id TEXT PRIMARY KEY,
+                BarPosition TEXT NOT NULL DEFAULT 'Bottom',
+                BarJustify TEXT NOT NULL DEFAULT 'Center'
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS SocialEntry (
+                Id TEXT PRIMARY KEY,
+                SocialsId TEXT NOT NULL REFERENCES Socials(Id) ON DELETE CASCADE,
+                Service TEXT NOT NULL,
+                Handle TEXT NOT NULL,
+                ProfileUrl TEXT NOT NULL,
+                SortOrder INTEGER NOT NULL DEFAULT 0
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Music (
+                Id TEXT PRIMARY KEY,
+                TrackPath TEXT NOT NULL,
+                IsEnabled INTEGER NOT NULL DEFAULT 0
+            );
+            """,
+            """
+            CREATE TABLE IF NOT EXISTS Settings (
+                Key TEXT PRIMARY KEY,
+                Value TEXT NOT NULL
+            );
+            """,
+        };
+        foreach (var sql in statements)
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = sql;
+            cmd.ExecuteNonQuery();
+        }
+        MigrateSourceTable();
+        MigrateWebcamConfigTable();
+        MigrateSceneTable();
+        MigrateSceneSocialBarColumn();
+        MigrateSocialsTable();
+        MigrateSocialEntryTable();
+        if (GetUserVersion() < 3)
+            MigrateToV3();
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA user_version = 9;";
+            cmd.ExecuteNonQuery();
+        }
+    }
+
+
+    // v1 → v2: Source gains ClipShape + IsMirrored (webcam clip/mirror prefs).
+    // CREATE TABLE IF NOT EXISTS doesn't touch existing tables, so pre-v2 DBs
+    // get the columns here instead.
+    private void MigrateSourceTable()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(Source);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (!columns.Contains("ClipShape"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ClipShape TEXT NOT NULL DEFAULT 'Traditional';";
+            cmd.ExecuteNonQuery();
+        }
+
+        if (!columns.Contains("IsMirrored"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN IsMirrored INTEGER NOT NULL DEFAULT 0;";
+            cmd.ExecuteNonQuery();
+        }
+
+        if (columns.Contains("IsBackdrop"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source RENAME COLUMN IsBackdrop TO IsBackground;";
+            cmd.ExecuteNonQuery();
+        }
+        else if (!columns.Contains("IsBackground"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN IsBackground INTEGER NOT NULL DEFAULT 0;";
+            cmd.ExecuteNonQuery();
+        }
+
+        if (!columns.Contains("CaptureKey"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN CaptureKey TEXT;";
+            cmd.ExecuteNonQuery();
+        }
+
+        // TASK 3.18: ChatBox overlay source
+        if (!columns.Contains("ChatFontSize"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatFontSize REAL NOT NULL DEFAULT 16;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatFontColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatFontColor TEXT NOT NULL DEFAULT '#FFFFFF';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatBackgroundColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatBackgroundColor TEXT NOT NULL DEFAULT '#80000000';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatMaxMessages"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatMaxMessages INTEGER NOT NULL DEFAULT 5;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatShowTimestamps"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatShowTimestamps INTEGER NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatShowBadges"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatShowBadges INTEGER NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatMemberColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatMemberColor TEXT NOT NULL DEFAULT '#e94560';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatSuperChatColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatSuperChatColor TEXT NOT NULL DEFAULT '#eab308';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ShowDesktop"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ShowDesktop INTEGER NOT NULL DEFAULT 0;";
+            cmd.ExecuteNonQuery();
+        }
+
+        if (!columns.Contains("WebUri"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN WebUri TEXT;";
+            cmd.ExecuteNonQuery();
+        }
+
+        // TASK 21: Media source (video/audio file playback)
+        if (!columns.Contains("MediaPath"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN MediaPath TEXT;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("MediaIsLooping"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN MediaIsLooping INTEGER NOT NULL DEFAULT 0;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("MediaVolume"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN MediaVolume REAL NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("MediaPlaybackState"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN MediaPlaybackState TEXT NOT NULL DEFAULT 'Stopped';";
+            cmd.ExecuteNonQuery();
+        }
+
+        // Rename legacy "Backdrop" display name to "Background" in existing rows
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "UPDATE Source SET Name = 'Background' WHERE Name = 'Backdrop';";
+            cmd.ExecuteNonQuery();
+        }
+    }
+
+    // v3 → v4: WebcamSceneConfig gains RectWidth/RectHeight (the pre-Round rect,
+    // so a reloaded Round webcam restores its aspect on toggle-back).
+    private void MigrateWebcamConfigTable()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(WebcamSceneConfig);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (!columns.Contains("RectWidth"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE WebcamSceneConfig ADD COLUMN RectWidth REAL;";
+            cmd.ExecuteNonQuery();
+        }
+
+        if (!columns.Contains("RectHeight"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE WebcamSceneConfig ADD COLUMN RectHeight REAL;";
+            cmd.ExecuteNonQuery();
+        }
+    }
+
+    // v2 → v3: the webcam leaves the Source table. Any webcam Source rows become
+    // one Webcam identity (first row — one camera app-wide) + a WebcamSceneConfig
+    // per scene that had one, then the webcam rows are deleted. No backfill:
+    // scenes without the webcam stay webcam-free.
+    private void MigrateToV3()
+    {
+        var rows = new List<(string Id, string SceneId, string Name, double X, double Y, double W, double H, double Opacity, string DeviceId, string ClipShape, bool IsMirrored)>();
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = """
+                SELECT Id, SceneId, Name, X, Y, Width, Height, Opacity, DeviceId, ClipShape, IsMirrored
+                FROM Source WHERE Type = 'Webcam' ORDER BY SortOrder;
+                """;
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+            {
+                rows.Add((
+                    reader.GetString(0),
+                    reader.GetString(1),
+                    reader.GetString(2),
+                    reader.GetDouble(3),
+                    reader.GetDouble(4),
+                    reader.GetDouble(5),
+                    reader.GetDouble(6),
+                    reader.GetDouble(7),
+                    reader.IsDBNull(8) ? string.Empty : reader.GetString(8),
+                    reader.GetString(9),
+                    reader.GetInt32(10) != 0));
+            }
+        }
+        if (rows.Count == 0) return;
+
+        using var tx = _connection.BeginTransaction();
+        var webcamId = Guid.NewGuid().ToString();
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "INSERT INTO Webcam (Id, DeviceId, Name) VALUES ($id, $device, $name);";
+            cmd.Transaction = tx;
+            cmd.Parameters.AddWithValue("$id", webcamId);
+            cmd.Parameters.AddWithValue("$device", rows[0].DeviceId);
+            cmd.Parameters.AddWithValue("$name", rows[0].Name);
+            cmd.ExecuteNonQuery();
+        }
+
+        foreach (var row in rows)
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = """
+                INSERT INTO WebcamSceneConfig
+                    (SceneId, WebcamId, IsVisible, X, Y, Width, Height, Opacity,
+                     ClipShape, IsMirrored, BorderColor, BorderOpacity, BorderWidth, BorderAnimation, SortOrder)
+                VALUES ($sceneId, $webcamId, 1, $x, $y, $w, $h, $opacity,
+                        $clip, $mirrored, NULL, 1, 0, 'None', 0);
+                """;
+            cmd.Transaction = tx;
+            cmd.Parameters.AddWithValue("$sceneId", row.SceneId);
+            cmd.Parameters.AddWithValue("$webcamId", webcamId);
+            cmd.Parameters.AddWithValue("$x", row.X);
+            cmd.Parameters.AddWithValue("$y", row.Y);
+            cmd.Parameters.AddWithValue("$w", row.W);
+            cmd.Parameters.AddWithValue("$h", row.H);
+            cmd.Parameters.AddWithValue("$opacity", row.Opacity);
+            cmd.Parameters.AddWithValue("$clip", row.ClipShape);
+            cmd.Parameters.AddWithValue("$mirrored", row.IsMirrored ? 1 : 0);
+            cmd.ExecuteNonQuery();
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Source WHERE Type = 'Webcam';";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        tx.Commit();
+    }
+
+    // v5 → v6: Scene gains HasBackground. Added columns default to true; the
+    // ONE-TIME backfill (runs only when the column is first added) turns every
+    // non-Live canonical scene off and drops their background sources — the fix for
+    // DBs saved before the Live-only policy. MainViewModel.NormalizeBackgrounds
+    // re-runs the same normalization on every load for DBs that miss the backfill.
+    private void MigrateSceneTable()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(Scene);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (columns.Contains("HasBackdrop"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Scene RENAME COLUMN HasBackdrop TO HasBackground;";
+            cmd.ExecuteNonQuery();
+        }
+        else if (columns.Contains("HasBackground"))
+        {
+            return;
+        }
+
+        if (!columns.Contains("HasBackground"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Scene ADD COLUMN HasBackground INTEGER NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+
+        const string noBackground = "('starting', 'brb', 'chat', 'ending')";
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = $"UPDATE Scene SET HasBackground = 0 WHERE LOWER(TRIM(Name)) IN {noBackground};";
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = $"""
+                DELETE FROM Source
+                WHERE IsBackground = 1 AND SceneId IN
+                    (SELECT Id FROM Scene WHERE LOWER(TRIM(Name)) IN {noBackground});
+                """;
+            cmd.ExecuteNonQuery();
+        }
+    }
+
+    // v6 → v7: Scene gains HasSocialBar (the per-scene social-bar toggle).
+    // Defaults to 0 (off) — the creator adds it explicitly via the footer [+].
+    private void MigrateSceneSocialBarColumn()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(Scene);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (columns.Contains("HasSocialBar")) return;
+
+        using var alter = _connection.CreateCommand();
+        alter.CommandText = "ALTER TABLE Scene ADD COLUMN HasSocialBar INTEGER NOT NULL DEFAULT 0;";
+        alter.ExecuteNonQuery();
+    }
+
+    // v7 → v8: Socials gains BarEnabled (the dialog's show/hide switch). The old
+    // BarJustify column stays for back-compat but is no longer read or written.
+    private void MigrateSocialsTable()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(Socials);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (columns.Contains("BarEnabled")) return;
+
+        using var alter = _connection.CreateCommand();
+        alter.CommandText = "ALTER TABLE Socials ADD COLUMN BarEnabled INTEGER NOT NULL DEFAULT 1;";
+        alter.ExecuteNonQuery();
+    }
+
+    // v8 → v9: SocialEntry gains Software (the fediverse instance's nodeinfo
+    // software name) so a reloaded entry still shows the right service logo.
+    private void MigrateSocialEntryTable()
+    {
+        var columns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "PRAGMA table_info(SocialEntry);";
+            using var reader = cmd.ExecuteReader();
+            while (reader.Read())
+                columns.Add(reader.GetString(1));
+        }
+
+        if (columns.Contains("Software")) return;
+
+        using var alter = _connection.CreateCommand();
+        alter.CommandText = "ALTER TABLE SocialEntry ADD COLUMN Software TEXT;";
+        alter.ExecuteNonQuery();
+    }
+}

Services/LayoutStore.Save.cs

@@ -0,0 +1,339 @@
+using Microsoft.Data.Sqlite;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+public partial class LayoutStore : IDisposable
+{
+    public void Save(IEnumerable<Scene> scenes, Webcam? webcam, SocialsConfig? socials, Music? music = null)
+    {
+        using var tx = _connection.BeginTransaction();
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM WebcamSceneConfig;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Source;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Webcam;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM SocialEntry;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Socials;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Music;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Scene;";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = """
+                INSERT INTO Scene (Id, Name, IsHidden, IsChatScene, HasBackground, HasSocialBar, SortOrder)
+                VALUES ($id, $name, $isHidden, $isChat, $hasBackground, $hasSocialBar, $sort)
+                """;
+            cmd.Transaction = tx;
+            var idP = cmd.Parameters.Add("$id", SqliteType.Text);
+            var nameP = cmd.Parameters.Add("$name", SqliteType.Text);
+            var hiddenP = cmd.Parameters.Add("$isHidden", SqliteType.Integer);
+            var chatP = cmd.Parameters.Add("$isChat", SqliteType.Integer);
+            var backgroundP = cmd.Parameters.Add("$hasBackground", SqliteType.Integer);
+            var socialBarP = cmd.Parameters.Add("$hasSocialBar", SqliteType.Integer);
+            var sortP = cmd.Parameters.Add("$sort", SqliteType.Integer);
+
+            var sort = 0;
+            foreach (var scene in scenes)
+            {
+                idP.Value = scene.Id;
+                nameP.Value = scene.Name;
+                hiddenP.Value = scene.IsHidden ? 1 : 0;
+                chatP.Value = scene.IsChatScene ? 1 : 0;
+                backgroundP.Value = scene.HasBackground ? 1 : 0;
+                socialBarP.Value = scene.HasSocialBar ? 1 : 0;
+                sortP.Value = sort++;
+                cmd.ExecuteNonQuery();
+            }
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = """
+                INSERT INTO Source (Id, SceneId, AssetId, Type, Name, IsEnabled,
+                                    X, Y, Width, Height, Opacity, MonitorIndex,
+                                    ClipShape, IsMirrored, IsBackground, CaptureKey, ShowDesktop, SortOrder,
+                                    ChatFontSize, ChatFontColor, ChatBackgroundColor, ChatMaxMessages,
+                                    ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor,
+                                    WebUri, MediaPath, MediaIsLooping, MediaVolume, MediaPlaybackState)
+                VALUES ($id, $sceneId, $assetId, $type, $name, $isEnabled,
+                        $x, $y, $w, $h, $opacity, $monitor,
+                        $clip, $mirrored, $isBackground, $captureKey, $showDesktop, $sort,
+                        $chatFontSize, $chatFontColor, $chatBgColor, $chatMaxMsgs,
+                        $chatTimestamps, $chatBadges, $chatMemberColor, $chatSuperChatColor,
+                        $webUri, $mediaPath, $mediaIsLooping, $mediaVolume, $mediaPlaybackState)
+                """;
+            cmd.Transaction = tx;
+            var idP = cmd.Parameters.Add("$id", SqliteType.Text);
+            var sceneIdP = cmd.Parameters.Add("$sceneId", SqliteType.Text);
+            var assetIdP = cmd.Parameters.Add("$assetId", SqliteType.Text);
+            var typeP = cmd.Parameters.Add("$type", SqliteType.Text);
+            var nameP = cmd.Parameters.Add("$name", SqliteType.Text);
+            var enabledP = cmd.Parameters.Add("$isEnabled", SqliteType.Integer);
+            var xP = cmd.Parameters.Add("$x", SqliteType.Real);
+            var yP = cmd.Parameters.Add("$y", SqliteType.Real);
+            var wP = cmd.Parameters.Add("$w", SqliteType.Real);
+            var hP = cmd.Parameters.Add("$h", SqliteType.Real);
+            var opacityP = cmd.Parameters.Add("$opacity", SqliteType.Real);
+            var monitorP = cmd.Parameters.Add("$monitor", SqliteType.Integer);
+            var clipP = cmd.Parameters.Add("$clip", SqliteType.Text);
+            var mirroredP = cmd.Parameters.Add("$mirrored", SqliteType.Integer);
+            var isBackgroundP = cmd.Parameters.Add("$isBackground", SqliteType.Integer);
+            var captureKeyP = cmd.Parameters.Add("$captureKey", SqliteType.Text);
+            var showDesktopP = cmd.Parameters.Add("$showDesktop", SqliteType.Integer);
+            var sortP = cmd.Parameters.Add("$sort", SqliteType.Integer);
+            var chatFontSizeP = cmd.Parameters.Add("$chatFontSize", SqliteType.Real);
+            var chatFontColorP = cmd.Parameters.Add("$chatFontColor", SqliteType.Text);
+            var chatBgColorP = cmd.Parameters.Add("$chatBgColor", SqliteType.Text);
+            var chatMaxMsgsP = cmd.Parameters.Add("$chatMaxMsgs", SqliteType.Integer);
+            var chatTimestampsP = cmd.Parameters.Add("$chatTimestamps", SqliteType.Integer);
+            var chatBadgesP = cmd.Parameters.Add("$chatBadges", SqliteType.Integer);
+            var chatMemberColorP = cmd.Parameters.Add("$chatMemberColor", SqliteType.Text);
+            var chatSuperChatColorP = cmd.Parameters.Add("$chatSuperChatColor", SqliteType.Text);
+            var webUriP = cmd.Parameters.Add("$webUri", SqliteType.Text);
+            var mediaPathP = cmd.Parameters.Add("$mediaPath", SqliteType.Text);
+            var mediaIsLoopingP = cmd.Parameters.Add("$mediaIsLooping", SqliteType.Integer);
+            var mediaVolumeP = cmd.Parameters.Add("$mediaVolume", SqliteType.Real);
+            var mediaPlaybackStateP = cmd.Parameters.Add("$mediaPlaybackState", SqliteType.Text);
+
+            foreach (var scene in scenes)
+            {
+                var sort = 0;
+                foreach (var element in scene.Elements)
+                {
+                    if (element is not Source source) continue;
+                    idP.Value = source.Id;
+                    sceneIdP.Value = scene.Id;
+                    assetIdP.Value = (object?)source.AssetId ?? DBNull.Value;
+                    typeP.Value = source.Type.ToString();
+                    nameP.Value = source.Name;
+                    enabledP.Value = source.IsEnabled ? 1 : 0;
+                    xP.Value = source.X;
+                    yP.Value = source.Y;
+                    wP.Value = source.Width;
+                    hP.Value = source.Height;
+                    opacityP.Value = source.Opacity;
+                    monitorP.Value = (object?)source.MonitorIndex ?? DBNull.Value;
+                    clipP.Value = source.ClipShape.ToString();
+                    mirroredP.Value = source.IsMirrored ? 1 : 0;
+                    isBackgroundP.Value = source.IsBackground ? 1 : 0;
+                    captureKeyP.Value = (object?)source.CaptureKey ?? DBNull.Value;
+                    showDesktopP.Value = source.ShowDesktop ? 1 : 0;
+                    sortP.Value = sort++;
+                    chatFontSizeP.Value = source.ChatFontSize;
+                    chatFontColorP.Value = source.ChatFontColor;
+                    chatBgColorP.Value = source.ChatBackgroundColor;
+                    chatMaxMsgsP.Value = source.ChatMaxMessages;
+                    chatTimestampsP.Value = source.ChatShowTimestamps ? 1 : 0;
+                    chatBadgesP.Value = source.ChatShowBadges ? 1 : 0;
+                    chatMemberColorP.Value = source.ChatMemberColor;
+                    chatSuperChatColorP.Value = source.ChatSuperChatColor;
+                    webUriP.Value = (object?)source.WebUri ?? DBNull.Value;
+                    mediaPathP.Value = (object?)source.MediaPath ?? DBNull.Value;
+                    mediaIsLoopingP.Value = source.MediaIsLooping ? 1 : 0;
+                    mediaVolumeP.Value = source.MediaVolume;
+                    mediaPlaybackStateP.Value = source.MediaPlaybackState.ToString();
+                    cmd.ExecuteNonQuery();
+                }
+            }
+        }
+
+        if (webcam != null)
+        {
+            using (var cmd = _connection.CreateCommand())
+            {
+                cmd.CommandText = "INSERT INTO Webcam (Id, DeviceId, Name) VALUES ($id, $device, $name);";
+                cmd.Transaction = tx;
+                cmd.Parameters.AddWithValue("$id", webcam.Id);
+                cmd.Parameters.AddWithValue("$device", webcam.DeviceId);
+                cmd.Parameters.AddWithValue("$name", webcam.Name);
+                cmd.ExecuteNonQuery();
+            }
+
+            using (var cmd = _connection.CreateCommand())
+            {
+                cmd.CommandText = """
+                    INSERT INTO WebcamSceneConfig
+                        (SceneId, WebcamId, IsVisible, X, Y, Width, Height, Opacity,
+                         ClipShape, IsMirrored, BorderColor, BorderOpacity, BorderWidth, BorderAnimation,
+                         RectWidth, RectHeight, SortOrder)
+                    VALUES ($sceneId, $webcamId, $isVisible, $x, $y, $w, $h, $opacity,
+                            $clip, $mirrored, $borderColor, $borderOpacity, $borderWidth, $borderAnimation,
+                            $rectWidth, $rectHeight, $sort)
+                    """;
+                cmd.Transaction = tx;
+                var sceneIdP = cmd.Parameters.Add("$sceneId", SqliteType.Text);
+                var webcamIdP = cmd.Parameters.Add("$webcamId", SqliteType.Text);
+                var visibleP = cmd.Parameters.Add("$isVisible", SqliteType.Integer);
+                var xP = cmd.Parameters.Add("$x", SqliteType.Real);
+                var yP = cmd.Parameters.Add("$y", SqliteType.Real);
+                var wP = cmd.Parameters.Add("$w", SqliteType.Real);
+                var hP = cmd.Parameters.Add("$h", SqliteType.Real);
+                var opacityP = cmd.Parameters.Add("$opacity", SqliteType.Real);
+                var clipP = cmd.Parameters.Add("$clip", SqliteType.Text);
+                var mirroredP = cmd.Parameters.Add("$mirrored", SqliteType.Integer);
+                var colorP = cmd.Parameters.Add("$borderColor", SqliteType.Text);
+                var borderOpacityP = cmd.Parameters.Add("$borderOpacity", SqliteType.Real);
+                var borderWidthP = cmd.Parameters.Add("$borderWidth", SqliteType.Integer);
+                var animationP = cmd.Parameters.Add("$borderAnimation", SqliteType.Text);
+                var rectWidthP = cmd.Parameters.Add("$rectWidth", SqliteType.Real);
+                var rectHeightP = cmd.Parameters.Add("$rectHeight", SqliteType.Real);
+                var sortP = cmd.Parameters.Add("$sort", SqliteType.Integer);
+
+                foreach (var scene in scenes)
+                {
+                    var sort = 0;
+                    foreach (var config in scene.Elements.OfType<WebcamSceneConfig>())
+                    {
+                        sceneIdP.Value = scene.Id;
+                        webcamIdP.Value = config.WebcamId;
+                        visibleP.Value = config.IsVisible ? 1 : 0;
+                        xP.Value = config.X;
+                        yP.Value = config.Y;
+                        wP.Value = config.Width;
+                        hP.Value = config.Height;
+                        opacityP.Value = config.Opacity;
+                        clipP.Value = config.ClipShape.ToString();
+                        mirroredP.Value = config.IsMirrored ? 1 : 0;
+                        colorP.Value = (object?)(string.IsNullOrEmpty(config.BorderColor) ? null : config.BorderColor) ?? DBNull.Value;
+                        borderOpacityP.Value = config.BorderOpacity;
+                        borderWidthP.Value = config.BorderWidth;
+                        animationP.Value = config.BorderAnimation.ToString();
+                        rectWidthP.Value = (object?)config.RectWidth ?? DBNull.Value;
+                        rectHeightP.Value = (object?)config.RectHeight ?? DBNull.Value;
+                        sortP.Value = sort++;
+                        cmd.ExecuteNonQuery();
+                    }
+                }
+            }
+        }
+
+        if (socials != null && socials.Entries.Count > 0)
+        {
+            var socialsId = Guid.NewGuid().ToString();
+            using (var cmd = _connection.CreateCommand())
+            {
+                cmd.CommandText = "INSERT INTO Socials (Id, BarPosition, BarEnabled) VALUES ($id, $pos, $enabled);";
+                cmd.Transaction = tx;
+                cmd.Parameters.AddWithValue("$id", socialsId);
+                cmd.Parameters.AddWithValue("$pos", socials.BarPosition.ToString());
+                cmd.Parameters.AddWithValue("$enabled", socials.BarEnabled ? 1 : 0);
+                cmd.ExecuteNonQuery();
+            }
+
+            using var entryCmd = _connection.CreateCommand();
+            entryCmd.CommandText = """
+                INSERT INTO SocialEntry (Id, SocialsId, Service, Handle, ProfileUrl, Software, SortOrder)
+                VALUES ($id, $socialsId, $service, $handle, $url, $software, $sort)
+                """;
+            entryCmd.Transaction = tx;
+            var eId = entryCmd.Parameters.Add("$id", SqliteType.Text);
+            var eSocialsId = entryCmd.Parameters.Add("$socialsId", SqliteType.Text);
+            var eService = entryCmd.Parameters.Add("$service", SqliteType.Text);
+            var eHandle = entryCmd.Parameters.Add("$handle", SqliteType.Text);
+            var eUrl = entryCmd.Parameters.Add("$url", SqliteType.Text);
+            var eSoftware = entryCmd.Parameters.Add("$software", SqliteType.Text);
+            var eSort = entryCmd.Parameters.Add("$sort", SqliteType.Integer);
+
+            var entrySort = 0;
+            foreach (var entry in socials.Entries)
+            {
+                eId.Value = Guid.NewGuid().ToString();
+                eSocialsId.Value = socialsId;
+                eService.Value = entry.Service.ToString();
+                eHandle.Value = entry.Handle;
+                eUrl.Value = entry.ProfileUrl;
+                eSoftware.Value = (object?)entry.FediverseSoftware ?? DBNull.Value;
+                eSort.Value = entrySort++;
+                entryCmd.ExecuteNonQuery();
+            }
+        }
+
+        if (music != null && !string.IsNullOrWhiteSpace(music.TrackPath))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "INSERT INTO Music (Id, TrackPath, IsEnabled) VALUES ($id, $path, $enabled);";
+            cmd.Transaction = tx;
+            cmd.Parameters.AddWithValue("$id", Guid.NewGuid().ToString());
+            cmd.Parameters.AddWithValue("$path", music.TrackPath);
+            cmd.Parameters.AddWithValue("$enabled", music.IsEnabled ? 1 : 0);
+            cmd.ExecuteNonQuery();
+        }
+
+        using (var cmd = _connection.CreateCommand())
+        {
+            cmd.CommandText = "DELETE FROM Asset WHERE Id NOT IN (SELECT AssetId FROM Source WHERE AssetId IS NOT NULL);";
+            cmd.Transaction = tx;
+            cmd.ExecuteNonQuery();
+        }
+
+        // Save custom background paths and use-default flags per background source
+        foreach (var scene in scenes)
+        {
+            var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+            if (bg == null) continue;
+
+            var pathKey = $"BackgroundPath_{bg.Id}";
+            if (!string.IsNullOrWhiteSpace(bg.CustomBackgroundPath))
+                UpsertSetting(pathKey, bg.CustomBackgroundPath);
+            else
+            {
+                using var del = _connection.CreateCommand();
+                del.CommandText = "DELETE FROM Settings WHERE Key = $key;";
+                del.Parameters.AddWithValue("$key", pathKey);
+                del.ExecuteNonQuery();
+            }
+
+            var defaultKey = $"BackgroundUseDefault_{bg.Id}";
+            UpsertSetting(defaultKey, bg.UseDefaultBackground ? "1" : "0");
+        }
+
+        // Purge background settings left behind by deleted/duplicated rows
+        // (TASK 25 heal drops extras; their keys must not accumulate).
+        using (var purge = _connection.CreateCommand())
+        {
+            purge.Transaction = tx;
+            purge.CommandText =
+                @"DELETE FROM Settings
+                  WHERE (Key LIKE 'BackgroundUseDefault\_%' ESCAPE '\'
+                      OR Key LIKE 'BackgroundPath\_%' ESCAPE '\')
+                  AND SUBSTR(Key, INSTR(Key, '_') + 1) NOT IN (SELECT Id FROM Source);";
+            purge.ExecuteNonQuery();
+        }
+
+        tx.Commit();
+    }
+}

Services/LayoutStore.Settings.cs

@@ -0,0 +1,292 @@
+using Microsoft.Data.Sqlite;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+public partial class LayoutStore : IDisposable
+{
+    /// <summary>The last picked mic source name, or null if never chosen. Restored
+    /// at startup so the sound bar reconnects to the same, already-vetted device.</summary>
+    public string? LoadMicSourceName()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'MicSourceName';";
+        var value = cmd.ExecuteScalar() as string;
+        return string.IsNullOrWhiteSpace(value) ? null : value;
+    }
+
+    public void SaveMicSourceName(string? name)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'MicSourceName';";
+        cmd.ExecuteNonQuery();
+        if (string.IsNullOrWhiteSpace(name))
+            return;
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('MicSourceName', $name);";
+        insert.Parameters.AddWithValue("$name", name);
+        insert.ExecuteNonQuery();
+    }
+
+    /// <summary>The user's chosen record output folder (TASK 18), or null to use the
+    /// default <c>%APPDATA%\ytLlive\recordings</c>. Restored at startup.</summary>
+    public string? LoadRecordFolder()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'RecordFolder';";
+        var value = cmd.ExecuteScalar() as string;
+        return string.IsNullOrWhiteSpace(value) ? null : value;
+    }
+
+    public void SaveRecordFolder(string? folder)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'RecordFolder';";
+        cmd.ExecuteNonQuery();
+        if (string.IsNullOrWhiteSpace(folder))
+            return;
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('RecordFolder', $folder);";
+        insert.Parameters.AddWithValue("$folder", folder);
+        insert.ExecuteNonQuery();
+    }
+
+    /// <summary>The cached reusable stream (TASK 5), or null if never created.
+    /// Survives restarts so the pump has its RTMP URL the moment go-live starts
+    /// instead of waiting on the YouTube round-trip.</summary>
+    public ReusableStream? LoadReusableStream()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'ReusableStream';";
+        var value = cmd.ExecuteScalar() as string;
+        if (string.IsNullOrWhiteSpace(value)) return null;
+
+        var parts = value.Split('\u001F');
+        return parts.Length == 3
+            ? new ReusableStream(parts[0], parts[1], parts[2])
+            : null;
+    }
+
+    public void SaveReusableStream(ReusableStream? stream)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'ReusableStream';";
+        cmd.ExecuteNonQuery();
+        if (stream == null) return;
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('ReusableStream', $value);";
+        insert.Parameters.AddWithValue("$value", $"{stream.Id}\u001F{stream.IngestionAddress}\u001F{stream.StreamName}");
+        insert.ExecuteNonQuery();
+    }
+
+    public string? LoadLicenseKey()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'LicenseKey';";
+        var value = cmd.ExecuteScalar() as string;
+        return string.IsNullOrWhiteSpace(value) ? null : value;
+    }
+
+    public void SaveLicenseKey(string? key)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'LicenseKey';";
+        cmd.ExecuteNonQuery();
+        if (string.IsNullOrWhiteSpace(key)) return;
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('LicenseKey', $value);";
+        insert.Parameters.AddWithValue("$value", key);
+        insert.ExecuteNonQuery();
+    }
+
+    /// <summary>When the license was last validated online (ISO 8601), or null if never.</summary>
+    public DateTime? LoadLicenseValidatedAt()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'LicenseValidatedAt';";
+        var value = cmd.ExecuteScalar() as string;
+        if (string.IsNullOrWhiteSpace(value)) return null;
+        return DateTime.TryParse(value, out var dt) ? dt : null;
+    }
+
+    public void SaveLicenseValidatedAt(DateTime? dt)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'LicenseValidatedAt';";
+        cmd.ExecuteNonQuery();
+        if (dt == null) return;
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('LicenseValidatedAt', $value);";
+        insert.Parameters.AddWithValue("$value", dt.Value.ToString("o"));
+        insert.ExecuteNonQuery();
+    }
+
+    /// <summary>Cached premium state (1 = premium, 0 = free). Used for offline
+    /// grace period — the app checks online at startup but uses this cached
+    /// value when offline.</summary>
+    public bool LoadIsPremium()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'IsPremium';";
+        var value = cmd.ExecuteScalar() as string;
+        return value == "1";
+    }
+
+    public void SaveIsPremium(bool isPremium)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = 'IsPremium';";
+        cmd.ExecuteNonQuery();
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ('IsPremium', $value);";
+        insert.Parameters.AddWithValue("$value", isPremium ? "1" : "0");
+        insert.ExecuteNonQuery();
+    }
+
+    public (string TransitionType, double DurationMs) LoadTransitionSettings()
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = 'TransitionType';";
+        var type = cmd.ExecuteScalar() as string;
+
+        using var cmd2 = _connection.CreateCommand();
+        cmd2.CommandText = "SELECT Value FROM Settings WHERE Key = 'TransitionDurationMs';";
+        var dur = cmd2.ExecuteScalar() as string;
+
+        return (type ?? "Fade", dur != null && double.TryParse(dur, out var d) ? d : 300);
+    }
+
+    public void SaveTransitionSettings(string transitionType, double durationMs)
+    {
+        UpsertSetting("TransitionType", transitionType);
+        UpsertSetting("TransitionDurationMs", durationMs.ToString("F0"));
+    }
+
+    // ─── Broadcast metadata (broadcast pull-out) + window geometry ───
+
+    public Models.BroadcastMetadata LoadBroadcastMetadata()
+    {
+        return new Models.BroadcastMetadata
+        {
+            Title = GetSetting("Broadcast.Title") ?? string.Empty,
+            Description = GetSetting("Broadcast.Description") ?? string.Empty,
+            TagsCsv = GetSetting("Broadcast.TagsCsv") ?? string.Empty,
+            Visibility = GetSetting("Broadcast.Visibility") ?? "private",
+            MadeForKids = GetSetting("Broadcast.MadeForKids") == "1",
+            ScheduledStartTime = DateTime.TryParse(GetSetting("Broadcast.ScheduledStartTime"), out var t) ? t : null,
+        };
+    }
+
+    public void SaveBroadcastMetadata(Models.BroadcastMetadata meta)
+    {
+        UpsertSetting("Broadcast.Title", meta.Title);
+        UpsertSetting("Broadcast.Description", meta.Description);
+        UpsertSetting("Broadcast.TagsCsv", meta.TagsCsv);
+        UpsertSetting("Broadcast.Visibility", meta.Visibility);
+        UpsertSetting("Broadcast.MadeForKids", meta.MadeForKids ? "1" : "0");
+        UpsertSetting("Broadcast.ScheduledStartTime",
+            meta.ScheduledStartTime?.ToString("o") ?? string.Empty);
+    }
+
+    // ─── Hotkey bindings (TASK 20 step 2) ───
+
+    /// <summary>
+    /// Load saved hotkey bindings. Returns only entries that have been explicitly
+    /// saved — missing HotkeyIds are unbound (not in the returned dictionary).
+    /// Caller fills in defaults for any missing entries as needed.
+    /// </summary>
+    public Dictionary<HotkeyId, HotkeyChord> LoadHotkeyBindings()
+    {
+        var result = new Dictionary<HotkeyId, HotkeyChord>();
+        foreach (HotkeyId id in Enum.GetValues(typeof(HotkeyId)))
+        {
+            var raw = GetSetting($"Hotkey.{id}");
+            if (raw == null) continue; // not saved = unbound
+            if (raw == "none") continue; // explicitly unbound
+            try
+            {
+                result[id] = HotkeyChord.ParseStorage(raw);
+            }
+            catch (FormatException)
+            {
+                // corrupt entry — skip, will fall back to default
+            }
+        }
+        return result;
+    }
+
+    /// <summary>
+    /// Save hotkey bindings. Null entries in the dictionary mean "unbound" (stored
+    /// as "none"). Only the provided entries are saved; previously saved entries
+    /// for HotkeyIds not in the dictionary are deleted.
+    /// </summary>
+    public void SaveHotkeyBindings(Dictionary<HotkeyId, HotkeyChord?> bindings)
+    {
+        // Delete all existing hotkey settings first
+        foreach (HotkeyId id in Enum.GetValues(typeof(HotkeyId)))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "DELETE FROM Settings WHERE Key = $key;";
+            cmd.Parameters.AddWithValue("$key", $"Hotkey.{id}");
+            cmd.ExecuteNonQuery();
+        }
+
+        // Save the new bindings
+        foreach (var (id, chord) in bindings)
+        {
+            var value = chord?.ToString() ?? "none";
+            UpsertSetting($"Hotkey.{id}", value);
+        }
+    }
+
+    public (double Left, double Top, double Width, double Height, string State)? LoadWindowState()
+    {
+        var left = GetSetting("Window.Left");
+        var top = GetSetting("Window.Top");
+        var width = GetSetting("Window.Width");
+        var height = GetSetting("Window.Height");
+        var state = GetSetting("Window.State");
+        if (left == null || top == null || width == null || height == null) return null;
+        if (!double.TryParse(left, out var l) || !double.TryParse(top, out var t) ||
+            !double.TryParse(width, out var w) || !double.TryParse(height, out var h))
+            return null;
+        return (l, t, w, h, state ?? "Normal");
+    }
+
+    public void SaveWindowState(double left, double top, double width, double height, string state)
+    {
+        UpsertSetting("Window.Left", left.ToString("F0"));
+        UpsertSetting("Window.Top", top.ToString("F0"));
+        UpsertSetting("Window.Width", width.ToString("F0"));
+        UpsertSetting("Window.Height", height.ToString("F0"));
+        UpsertSetting("Window.State", state);
+    }
+
+    private string? GetSetting(string key)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "SELECT Value FROM Settings WHERE Key = $key;";
+        cmd.Parameters.AddWithValue("$key", key);
+        return cmd.ExecuteScalar() as string;
+    }
+
+    private void UpsertSetting(string key, string value)
+    {
+        using var cmd = _connection.CreateCommand();
+        cmd.CommandText = "DELETE FROM Settings WHERE Key = $key;";
+        cmd.Parameters.AddWithValue("$key", key);
+        cmd.ExecuteNonQuery();
+
+        using var insert = _connection.CreateCommand();
+        insert.CommandText = "INSERT INTO Settings (Key, Value) VALUES ($key, $value);";
+        insert.Parameters.AddWithValue("$key", key);
+        insert.Parameters.AddWithValue("$value", value);
+        insert.ExecuteNonQuery();
+    }
+}

ViewModels/MainViewModel.Background.Model.cs

@@ -0,0 +1,164 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    internal static System.Windows.Media.Imaging.BitmapSource? LoadBackgroundImage(Scene scene)
+    {
+        var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+        if (bg != null && !bg.UseDefaultBackground
+            && !string.IsNullOrWhiteSpace(bg.CustomBackgroundPath)
+            && System.IO.File.Exists(bg.CustomBackgroundPath))
+        {
+            try
+            {
+                var bitmap = new System.Windows.Media.Imaging.BitmapImage();
+                bitmap.BeginInit();
+                bitmap.UriSource = new Uri(bg.CustomBackgroundPath);
+                bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
+                bitmap.EndInit();
+                bitmap.Freeze();
+                return bitmap;
+            }
+            catch { /* fall through to AssetId */ }
+        }
+        if (bg != null && !string.IsNullOrWhiteSpace(bg.AssetId))
+            return ImageCache.Get(bg.AssetId);
+        return null;
+    }
+
+    private static BitmapSource CreatePlaceholderSnapshot(string sceneName)
+    {
+        var colors = new Dictionary<string, System.Windows.Media.Brush>(StringComparer.OrdinalIgnoreCase)
+        {
+            ["Starting"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(233, 69, 96)),
+            ["Live"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(34, 197, 94)),
+            ["BRB"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(234, 179, 8)),
+            ["Chat"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(59, 130, 246)),
+            ["Ending"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(168, 85, 247)),
+        };
+        var brush = colors.TryGetValue(sceneName, out var c) ? c
+            : new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(60, 60, 80));
+        var dv = new System.Windows.Media.DrawingVisual();
+        using (var ctx = dv.RenderOpen())
+        {
+            ctx.DrawRectangle(brush, null, new System.Windows.Rect(0, 0, 320, 180));
+            var ft = new System.Windows.Media.FormattedText(
+                sceneName,
+                System.Globalization.CultureInfo.InvariantCulture,
+                System.Windows.FlowDirection.LeftToRight,
+                new System.Windows.Media.Typeface("Segoe UI"),
+                18,
+                System.Windows.Media.Brushes.White,
+                96);
+            ctx.DrawText(ft, new System.Windows.Point(160 - ft.Width / 2, 90 - ft.Height / 2));
+        }
+        var rtb = new System.Windows.Media.Imaging.RenderTargetBitmap(
+            320, 180, 96, 96, System.Windows.Media.PixelFormats.Pbgra32);
+        rtb.Render(dv);
+        rtb.Freeze();
+        return rtb;
+    }
+
+    // ─── Screen background capture (live desktop/game) ───
+
+    private const string MonitorKeyPrefix = "monitor:";
+
+    /// <summary>Every background-enabled scene has exactly one background, kept at index 0 (bottom layer).
+    /// Returns null for a scene with <see cref="Scene.HasBackground"/> = false.</summary>
+    internal static Source? EnsureBackground(Scene scene)
+    {
+        if (!scene.HasBackground) return null;
+        var background = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
+        if (background != null) return background;
+
+        background = CreateBackground(scene.Name);
+        scene.Elements.Insert(0, background);
+        return background;
+    }
+
+    /// <summary>The one Background row for a scene. Live gets the capture flavor
+    /// (Show Desktop / monitor switch / fullscreen-game detect) falling back to
+    /// live-background.jpg; every other screen is a static default-art layer.
+    /// Both are named "Background" — the user never sees capture jargon here.</summary>
+    internal static Source CreateBackground(string sceneName)
+    {
+        var isLive = SceneCatalog.Is(sceneName, SceneCatalog.Live);
+        return new Source
+        {
+            Name = "Background",
+            Type = isLive ? SourceType.DisplayCapture : SourceType.Background,
+            IsBackground = true,
+            IsEnabled = true,
+            X = 0,
+            Y = 0,
+            Width = MasterFrameWidth,
+            Height = MasterFrameHeight,
+        };
+    }
+
+    /// <summary>Heals any loaded layout to the locked Background model: exactly
+    /// one Background per canonical scene, correct flavor for the scene (static
+    /// art everywhere, DisplayCapture on Live only), at index 0, named
+    /// "Background". Duplicates and stale rows are dropped; missing ones seeded;
+    /// non-canonical scenes get HasBackground=false and lose any backgrounds.</summary>
+    internal static void NormalizeBackgrounds(IEnumerable<Scene> scenes)
+    {
+        foreach (var scene in scenes)
+        {
+            if (!SceneCatalog.HasBackground(scene.Name))
+            {
+                scene.HasBackground = false;
+                foreach (var stale in scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList())
+                    scene.Elements.Remove(stale);
+                continue;
+            }
+
+            scene.HasBackground = true;
+            var isLive = SceneCatalog.Is(scene.Name, SceneCatalog.Live);
+            var wantedType = isLive ? SourceType.DisplayCapture : SourceType.Background;
+
+            var candidates = scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList();
+            var keep = candidates.FirstOrDefault(b => b.Type == wantedType) ?? candidates.FirstOrDefault();
+
+            foreach (var extra in candidates.Where(b => !ReferenceEquals(b, keep)))
+                scene.Elements.Remove(extra);
+
+            if (keep == null)
+            {
+                keep = CreateBackground(scene.Name);
+                scene.Elements.Insert(0, keep);
+            }
+
+            // Source.Type's setter derives IsBackground from the enum, so a
+            // flavor correction must re-assert the flag afterwards.
+            if (keep.Type != wantedType)
+            {
+                keep.Type = wantedType;
+                keep.IsBackground = true;
+            }
+
+            keep.Name = "Background";
+            keep.IsEnabled = true;
+
+            var index = scene.Elements.IndexOf(keep);
+            if (index > 0)
+                scene.Elements.Move(index, 0);
+        }
+    }
+
+    // Only the Live screen's background is a real-time surface. Every other
+    // lookup below (auto-capture, focus hooks, refresh) must ignore the static
+    // default-art rows so they can never start a desktop capture session.
+    private IEnumerable<Source> AllBackgrounds()
+        => Scenes.Where(s => SceneCatalog.Is(s.Name, SceneCatalog.Live))
+            .SelectMany(s => s.Elements.OfType<Source>().Where(x => x.IsBackground));
+}

ViewModels/MainViewModel.Background.cs

@@ -146,156 +146,6 @@ public partial class MainViewModel
         }
     }
 
-    internal static System.Windows.Media.Imaging.BitmapSource? LoadBackgroundImage(Scene scene)
-    {
-        var bg = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
-        if (bg != null && !bg.UseDefaultBackground
-            && !string.IsNullOrWhiteSpace(bg.CustomBackgroundPath)
-            && System.IO.File.Exists(bg.CustomBackgroundPath))
-        {
-            try
-            {
-                var bitmap = new System.Windows.Media.Imaging.BitmapImage();
-                bitmap.BeginInit();
-                bitmap.UriSource = new Uri(bg.CustomBackgroundPath);
-                bitmap.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
-                bitmap.EndInit();
-                bitmap.Freeze();
-                return bitmap;
-            }
-            catch { /* fall through to AssetId */ }
-        }
-        if (bg != null && !string.IsNullOrWhiteSpace(bg.AssetId))
-            return ImageCache.Get(bg.AssetId);
-        return null;
-    }
-
-    private static BitmapSource CreatePlaceholderSnapshot(string sceneName)
-    {
-        var colors = new Dictionary<string, System.Windows.Media.Brush>(StringComparer.OrdinalIgnoreCase)
-        {
-            ["Starting"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(233, 69, 96)),
-            ["Live"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(34, 197, 94)),
-            ["BRB"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(234, 179, 8)),
-            ["Chat"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(59, 130, 246)),
-            ["Ending"] = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(168, 85, 247)),
-        };
-        var brush = colors.TryGetValue(sceneName, out var c) ? c
-            : new System.Windows.Media.SolidColorBrush(System.Windows.Media.Color.FromRgb(60, 60, 80));
-        var dv = new System.Windows.Media.DrawingVisual();
-        using (var ctx = dv.RenderOpen())
-        {
-            ctx.DrawRectangle(brush, null, new System.Windows.Rect(0, 0, 320, 180));
-            var ft = new System.Windows.Media.FormattedText(
-                sceneName,
-                System.Globalization.CultureInfo.InvariantCulture,
-                System.Windows.FlowDirection.LeftToRight,
-                new System.Windows.Media.Typeface("Segoe UI"),
-                18,
-                System.Windows.Media.Brushes.White,
-                96);
-            ctx.DrawText(ft, new System.Windows.Point(160 - ft.Width / 2, 90 - ft.Height / 2));
-        }
-        var rtb = new System.Windows.Media.Imaging.RenderTargetBitmap(
-            320, 180, 96, 96, System.Windows.Media.PixelFormats.Pbgra32);
-        rtb.Render(dv);
-        rtb.Freeze();
-        return rtb;
-    }
-
-    // ─── Screen background capture (live desktop/game) ───
-
-    private const string MonitorKeyPrefix = "monitor:";
-
-    /// <summary>Every background-enabled scene has exactly one background, kept at index 0 (bottom layer).
-    /// Returns null for a scene with <see cref="Scene.HasBackground"/> = false.</summary>
-    internal static Source? EnsureBackground(Scene scene)
-    {
-        if (!scene.HasBackground) return null;
-        var background = scene.Elements.OfType<Source>().FirstOrDefault(s => s.IsBackground);
-        if (background != null) return background;
-
-        background = CreateBackground(scene.Name);
-        scene.Elements.Insert(0, background);
-        return background;
-    }
-
-    /// <summary>The one Background row for a scene. Live gets the capture flavor
-    /// (Show Desktop / monitor switch / fullscreen-game detect) falling back to
-    /// live-background.jpg; every other screen is a static default-art layer.
-    /// Both are named "Background" — the user never sees capture jargon here.</summary>
-    internal static Source CreateBackground(string sceneName)
-    {
-        var isLive = SceneCatalog.Is(sceneName, SceneCatalog.Live);
-        return new Source
-        {
-            Name = "Background",
-            Type = isLive ? SourceType.DisplayCapture : SourceType.Background,
-            IsBackground = true,
-            IsEnabled = true,
-            X = 0,
-            Y = 0,
-            Width = MasterFrameWidth,
-            Height = MasterFrameHeight,
-        };
-    }
-
-    /// <summary>Heals any loaded layout to the locked Background model: exactly
-    /// one Background per canonical scene, correct flavor for the scene (static
-    /// art everywhere, DisplayCapture on Live only), at index 0, named
-    /// "Background". Duplicates and stale rows are dropped; missing ones seeded;
-    /// non-canonical scenes get HasBackground=false and lose any backgrounds.</summary>
-    internal static void NormalizeBackgrounds(IEnumerable<Scene> scenes)
-    {
-        foreach (var scene in scenes)
-        {
-            if (!SceneCatalog.HasBackground(scene.Name))
-            {
-                scene.HasBackground = false;
-                foreach (var stale in scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList())
-                    scene.Elements.Remove(stale);
-                continue;
-            }
-
-            scene.HasBackground = true;
-            var isLive = SceneCatalog.Is(scene.Name, SceneCatalog.Live);
-            var wantedType = isLive ? SourceType.DisplayCapture : SourceType.Background;
-
-            var candidates = scene.Elements.OfType<Source>().Where(s => s.IsBackground).ToList();
-            var keep = candidates.FirstOrDefault(b => b.Type == wantedType) ?? candidates.FirstOrDefault();
-
-            foreach (var extra in candidates.Where(b => !ReferenceEquals(b, keep)))
-                scene.Elements.Remove(extra);
-
-            if (keep == null)
-            {
-                keep = CreateBackground(scene.Name);
-                scene.Elements.Insert(0, keep);
-            }
-
-            // Source.Type's setter derives IsBackground from the enum, so a
-            // flavor correction must re-assert the flag afterwards.
-            if (keep.Type != wantedType)
-            {
-                keep.Type = wantedType;
-                keep.IsBackground = true;
-            }
-
-            keep.Name = "Background";
-            keep.IsEnabled = true;
-
-            var index = scene.Elements.IndexOf(keep);
-            if (index > 0)
-                scene.Elements.Move(index, 0);
-        }
-    }
-
-    // Only the Live screen's background is a real-time surface. Every other
-    // lookup below (auto-capture, focus hooks, refresh) must ignore the static
-    // default-art rows so they can never start a desktop capture session.
-    private IEnumerable<Source> AllBackgrounds()
-        => Scenes.Where(s => SceneCatalog.Is(s.Name, SceneCatalog.Live))
-            .SelectMany(s => s.Elements.OfType<Source>().Where(x => x.IsBackground));
 
     // Full-screen game on its monitor, else null (static bg fallback — no
     // infinity mirror). Called at launch (from ReacquireScreenCaptures, before
@@ -565,4 +415,4 @@ public partial class MainViewModel
         }
         catch { /* non-critical — the app works without default art */ }
     }
-}
+}

ViewModels/MainViewModel.Chat.cs

@@ -1,7 +1,5 @@
 using System.Collections.ObjectModel;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Threading;
+using System.Linq;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
@@ -11,22 +9,12 @@ namespace ytLive.ViewModels;
 public partial class MainViewModel : ViewModelBase
 {
 
-    private readonly ChatBoxRenderer _chatBoxRenderer;
+    private readonly ChatOverlayLayer _chatLayer;
 
-    // Mock chat messages for the ChatBox preview — branded placeholders so the
-    // creator sees where the overlay lands before going live.
-    private static readonly IReadOnlyList<ChatMessage> MockChatMessages = new[]
-    {
-        new ChatMessage { AuthorName = "LlamaCasty", Message = "welcome to the stream!", Timestamp = DateTime.Now.AddMinutes(-4), IsMember = true },
-        new ChatMessage { AuthorName = "LlamaCastyFan", Message = "$10 — LlamaCasty is the best!", Timestamp = DateTime.Now.AddMinutes(-3), IsSuperChat = true },
-        new ChatMessage { AuthorName = "GamerDude", Message = "what streaming software is this?", Timestamp = DateTime.Now.AddMinutes(-2) },
-        new ChatMessage { AuthorName = "LlamaCasty", Message = "thanks for watching! llamacasty.com", Timestamp = DateTime.Now.AddMinutes(-1), IsMember = true },
-        new ChatMessage { AuthorName = "LlamaDog", Message = "Subscribe so they can buy the subscription at llamacasty.com!", Timestamp = DateTime.Now, IsMember = true },
-    };
-    // Chat fade timer: clears chat overlay after N seconds of inactivity.
-    private System.Windows.Threading.DispatcherTimer? _chatFadeTimer;
-
-    public ObservableCollection<ChatMessage> ChatMessages { get; } = new();
+    /// <summary>The live chat message buffer — the same collection the
+    /// <see cref="ChatOverlayLayer"/> owns; here so XAML can bind it and the
+    /// left panel can subscribe to its changes.</summary>
+    public ObservableCollection<ChatMessage> ChatMessages => _chatLayer.Messages;
 
     /// <summary>The Add → YouTube Chat menu item: enabled only while no chat layer exists
     /// anywhere — one chat overlay per layout.</summary>
@@ -37,158 +25,20 @@ public partial class MainViewModel : ViewModelBase
     public bool ShowChatInactiveMessage => !IsLive;
 
     private void OnChatMessageReceived(ChatMessage message)
-    {
-        System.Windows.Application.Current.Dispatcher.Invoke(() =>
-        {
-            ChatMessages.Add(message);
-            if (ChatMessages.Count > 500)
-                ChatMessages.RemoveAt(0);
+        => _chatLayer.OnMessageReceived(message, Scenes);
 
-            // Reset chat fade timer on every message
-            ResetChatFadeTimer();
-
-            StopMockChatPreview();
-
-            // Switch ChatBox previews from mock to real messages
-            if (StagedScene != null)
-                foreach (var chatBox in StagedScene.Elements.OfType<Source>().Where(s => s.Type == SourceType.ChatBox))
-                    UpdateChatBoxPreview(chatBox);
-        });
-    }
-
-    private void ResetChatFadeTimer()
-    {
-        _chatFadeTimer?.Stop();
-        var chatBoxes = Scenes.SelectMany(s => s.Elements).OfType<Source>()
-            .Where(s => s.Type == SourceType.ChatBox && s.ChatFadeSeconds > 0).ToList();
-        if (chatBoxes.Count == 0) return;
-
-        var delay = chatBoxes.Min(s => s.ChatFadeSeconds);
-        _chatFadeTimer = new System.Windows.Threading.DispatcherTimer
-        { Interval = TimeSpan.FromSeconds(delay) };
-        _chatFadeTimer.Tick += (_, _) =>
-        {
-            _chatFadeTimer?.Stop();
-            _chatFadeTimer = null;
-            ChatMessages.Clear();
-            foreach (var chatBox in Scenes.SelectMany(s => s.Elements).OfType<Source>()
-                         .Where(s => s.Type == SourceType.ChatBox))
-                UpdateChatBoxPreview(chatBox);
-            StartMockChatPreview();
-        };
-        _chatFadeTimer.Start();
-    }
+    private void UpdateChatBoxPreview(Source chatBox, IReadOnlyList<ChatMessage>? messages = null)
+        => _chatLayer.UpdatePreview(chatBox, messages);
 
     private VideoFrame? RenderChatBox(Source chatBox)
-    {
-        if (ChatMessages.Count == 0) return null;
-
-        var width = (int)Math.Max(1, chatBox.Width);
-        var height = (int)Math.Max(1, chatBox.Height);
-
-        return _chatBoxRenderer.Render(
-            ChatMessages,
-            width,
-            height,
-            chatBox.ChatFontSize,
-            chatBox.ChatFontFamily,
-            chatBox.ChatFontColor,
-            chatBox.ChatBackgroundColor,
-            chatBox.ChatMaxMessages,
-            chatBox.ChatShowTimestamps,
-            chatBox.ChatShowBadges,
-            chatBox.ChatMemberColor,
-            chatBox.ChatSuperChatColor);
-    }
-
-    /// <summary>
-    /// Renders the ChatBox preview: real messages when connected, mock when not.
-    /// </summary>
-    private void UpdateChatBoxPreview(Source chatBox, IReadOnlyList<ChatMessage>? messages = null)
-    {
-        try
-        {
-            messages ??= ChatMessages.Count > 0 ? (IReadOnlyList<ChatMessage>)ChatMessages : MockChatMessages;
-            var width = (int)Math.Max(32, chatBox.Width);
-            var height = (int)Math.Max(32, chatBox.Height);
-
-            var frame = _chatBoxRenderer.Render(
-                messages,
-                width,
-                height,
-                chatBox.ChatFontSize,
-                chatBox.ChatFontFamily,
-                chatBox.ChatFontColor,
-                chatBox.ChatBackgroundColor,
-                chatBox.ChatMaxMessages,
-                chatBox.ChatShowTimestamps,
-                chatBox.ChatShowBadges,
-                chatBox.ChatMemberColor,
-                chatBox.ChatSuperChatColor);
-
-            var bitmap = new WriteableBitmap(width, height, 96, 96, System.Windows.Media.PixelFormats.Bgra32, null);
-            bitmap.WritePixels(new System.Windows.Int32Rect(0, 0, width, height), frame.BgraPixels, frame.Stride, 0);
-            chatBox.VideoImageSource = bitmap;
-        }
-        catch (Exception ex) { AppLog.Write($"UpdateChatBoxPreview failed: {ex.Message}"); }
-    }
-
-    private CancellationTokenSource? _mockChatCts;
-
-    private async Task RunMockChatPreviewAsync(Source chatBox, CancellationToken ct)
-    {
-        var n = 0;
-        while (!ct.IsCancellationRequested)
-        {
-            UpdateChatBoxPreview(chatBox, MockChatMessages.Take(n + 1).ToList());
-            await Task.Delay(1000, ct);
-            n++;
-            if (n == MockChatMessages.Count)
-            {
-                await Task.Delay(3000, ct);
-                n = 0;
-            }
-        }
-    }
+        => _chatLayer.RenderFrame(chatBox);
 
     private void StartMockChatPreview()
-    {
-        StopMockChatPreview();
-        _mockChatCts = new CancellationTokenSource();
-        var ct = _mockChatCts.Token;
-        foreach (var chatBox in Scenes.SelectMany(s => s.Elements).OfType<Source>()
-                     .Where(s => s.Type == SourceType.ChatBox && s.ChatPreviewEnabled))
-            _ = RunMockChatPreviewAsync(chatBox, ct);
-    }
+        => _chatLayer.StartMockPreview(Scenes);
 
     private void StopMockChatPreview()
-    {
-        _mockChatCts?.Cancel();
-        _mockChatCts?.Dispose();
-        _mockChatCts = null;
-    }
+        => _chatLayer.StopMockPreview();
 
-    /// <summary>
-    /// Render previews + wire property-change subscriptions for all ChatBox
-    /// sources across every scene. Called after layout load so existing ChatBox
-    /// sources show mock content and respond to config changes.
-    /// </summary>
     private void UpdateActiveChatBoxPreviews()
-    {
-        foreach (var scene in Scenes)
-            foreach (var chatBox in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.ChatBox))
-            {
-                chatBox.PropertyChanged += (_, e) =>
-                {
-                    if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
-                        or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
-                        or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
-                        or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
-                        or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
-                        or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
-                        UpdateChatBoxPreview(chatBox);
-                };
-                UpdateChatBoxPreview(chatBox);
-            }
-    }
+        => _chatLayer.UpdateConfiguredBoxes(Scenes);
 }

ViewModels/MainViewModel.Recording.cs

@@ -0,0 +1,121 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Services;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+    private string? _recordFolder;
+    public string RecordFolderDisplay => _recordFolder ?? DefaultRecordFolder();
+    private string? _activeRecordPath;
+    private DateTime _recordStartTime;
+    private TimeSpan _recordLength;
+
+    private string? StartRecordFile()
+    {
+        try
+        {
+            var folder = _recordFolder ?? DefaultRecordFolder();
+            Directory.CreateDirectory(folder);
+            var name = RecordingFile.BuildStartName(DateTime.Now) + ".mp4";
+            var path = Path.Combine(folder, name);
+            _activeRecordPath = path;
+            return path;
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "Recording: failed to prepare output path");
+            return null;
+        }
+    }
+
+    private async Task FinalizeRecordingAsync()
+    {
+        var startPath = _activeRecordPath;
+        _activeRecordPath = null;
+        if (string.IsNullOrEmpty(startPath)) return;
+        try
+        {
+            while (_framePump.IsRunning) await Task.Delay(50);
+
+            if (!File.Exists(startPath))
+            {
+                AppLog.Write($"Recording: output not found for rename: {startPath}");
+                return;
+            }
+            _recordLength = _liveElapsed;
+            var autoStem = RecordingFile.BuildFinalName(_recordStartTime, _recordLength);
+            var dir = Path.GetDirectoryName(startPath)!;
+
+            // Manual rename modal: give the creator a chance to name the recording;
+            // null = keep the auto name (or the default recorded above).
+            string stem = autoStem;
+            var dialog = new RenameRecordingDialog(autoStem);
+            if (dialog.ShowDialog() == true && !string.IsNullOrEmpty(dialog.ResultFileName))
+                stem = dialog.ResultFileName;
+
+            var finalPath = UniquePath(Path.Combine(dir, stem + ".mp4"));
+            File.Move(startPath, finalPath);
+            AppLog.Write($"Recording saved: {finalPath}");
+            _notifications.Info("Recording saved",
+                Path.GetFileName(finalPath) + " — you can rename it in your videos folder at any time.");
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write(ex, "Recording: rename-on-stop failed");
+            _notifications.Error("Recording saved",
+                $"The recording was written but couldn't be renamed: {Path.GetFileName(startPath)}");
+        }
+    }
+
+    private static string UniquePath(string path)
+    {
+        if (!File.Exists(path)) return path;
+        var dir = Path.GetDirectoryName(path)!;
+        var name = Path.GetFileNameWithoutExtension(path);
+        var ext = Path.GetExtension(path);
+        for (var i = 2; ; i++)
+        {
+            var candidate = Path.Combine(dir, $"{name}-{i}{ext}");
+            if (!File.Exists(candidate)) return candidate;
+        }
+    }
+
+    private void ChooseRecordFolder()
+    {
+        var dialog = new Microsoft.Win32.OpenFolderDialog
+        {
+            Title = "Choose a folder for local recordings",
+            InitialDirectory = _recordFolder ?? DefaultRecordFolder(),
+        };
+        if (dialog.ShowDialog() == true)
+        {
+            _recordFolder = dialog.FolderName;
+            _layoutStore.SaveRecordFolder(_recordFolder);
+            OnPropertyChanged(nameof(RecordFolderDisplay));
+            _notifications.Info("Record folder set", _recordFolder);
+        }
+    }
+
+    private void ResetRecordFolder()
+    {
+        _recordFolder = null;
+        _layoutStore.SaveRecordFolder(null);
+        OnPropertyChanged(nameof(RecordFolderDisplay));
+        _notifications.Info("Record folder reset", RecordFolderDisplay);
+    }
+
+    internal static string DefaultRecordFolder()
+    {
+        var downloads = Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
+        return Directory.Exists(downloads)
+            ? downloads
+            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
+    }
+}

ViewModels/MainViewModel.Sources.cs

@@ -0,0 +1,251 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private void AddSource(object? parameter)
+    {
+        var scene = StagedScene;
+        if (scene == null) return;
+
+        var sourceType = parameter is SourceType typed
+            ? typed
+            : Enum.TryParse<SourceType>(parameter?.ToString(), true, out var parsed) ? parsed : SourceType.Image;
+        var baseName = sourceType switch
+        {
+            SourceType.Image => "Image",
+            SourceType.TextOverlay => "Text",
+            SourceType.Countdown => "Countdown",
+            SourceType.WebSource => "Web Resource",
+            SourceType.ChatBox => "YouTube Chat",
+            _ => "Layer",
+        };
+
+        // The (+) menu only adds regular layers. The Background is a locked
+        // per-screen layer managed by EnsureBackground/NormalizeBackgrounds —
+        // never user-created, never deleted. YouTube Chat is one-per-layout.
+        if (sourceType is SourceType.DisplayCapture or SourceType.WindowCapture or SourceType.Background)
+            return;
+        if (sourceType == SourceType.ChatBox && !CanAddYouTubeChat)
+            return;
+
+        // Web resources use "Web Resource-N" naming (0-indexed per scene)
+        var webCount = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.WebSource);
+        var source = new Source
+        {
+            Name = sourceType == SourceType.WebSource
+                ? $"{baseName}-{webCount}"
+                : NextSourceName(scene, baseName),
+            Type = sourceType,
+            X = sourceType == SourceType.ChatBox ? 1400 : 0,
+            Y = sourceType == SourceType.ChatBox ? 20 : 0,
+            Width = sourceType == SourceType.WebSource ? 640 : sourceType == SourceType.ChatBox ? 500 : 0,
+            Height = sourceType == SourceType.WebSource ? 480 : sourceType == SourceType.ChatBox ? 648 : 0,
+        };
+        scene.Elements.Add(source);
+
+        if (sourceType == SourceType.WebSource)
+        {
+            _webView2Manager?.Register(source);
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName == nameof(Source.WebUri))
+                    _webView2Manager?.OnWebUriChanged(source);
+            };
+        }
+
+        if (sourceType == SourceType.ChatBox)
+        {
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
+                    or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
+                    or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
+                    or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
+                    or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
+                    or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
+                    UpdateChatBoxPreview(source);
+            };
+            UpdateChatBoxPreview(source);
+        }
+
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+
+    // Duplicate resource names get an incrementing suffix with no space: Image,
+    // Image2, Image3… The next free number is derived from the names actually in
+    // the scene, so deleting a middle resource never collides with a survivor.
+    private static string NextSourceName(Scene scene, string baseName)
+    {
+        var taken = scene.Elements.OfType<Source>()
+            .Select(s => s.Name)
+            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
+                || (n.Length > baseName.Length
+                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
+                    && int.TryParse(n.Substring(baseName.Length), out _)))
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+        if (!taken.Contains(baseName)) return baseName;
+        for (var i = 2; ; i++)
+            if (!taken.Contains($"{baseName}{i}"))
+                return $"{baseName}{i}";
+    }
+
+    private void AddImage()
+    {
+        var scene = StagedScene;
+        if (scene == null) return;
+
+        var candidates = BuildImageCandidates();
+        if (candidates.Count == 0)
+        {
+            var bytes = PickImageBytes("Choose an image");
+            if (bytes != null) AddImageSource(bytes);
+            return;
+        }
+
+        var dialog = new ReuseImageDialog(new ReuseImageViewModel(candidates))
+        {
+            Owner = Application.Current.MainWindow
+        };
+        if (dialog.ShowDialog() != true) return;
+
+        if (dialog.WantsNew)
+        {
+            var bytes = PickImageBytes("Choose an image");
+            if (bytes != null) AddImageSource(bytes);
+        }
+        else
+        {
+            AddReusedImage(dialog.PickedAssetId!);
+        }
+    }
+
+    private List<ReuseImageCandidate> BuildImageCandidates()
+    {
+        var candidates = new List<ReuseImageCandidate>();
+        foreach (var scene in Scenes)
+        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.Image && !string.IsNullOrWhiteSpace(s.AssetId)))
+        {
+            candidates.Add(new ReuseImageCandidate
+            {
+                SceneName = scene.Name,
+                SourceName = source.Name,
+                AssetId = source.AssetId!
+            });
+        }
+        return candidates;
+    }
+
+    private byte[]? PickImageBytes(string title)
+    {
+        var dialog = new OpenFileDialog
+        {
+            Title = title,
+            Filter = "Image files (*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp)|*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp|All files (*.*)|*.*"
+        };
+        if (dialog.ShowDialog() != true) return null;
+        try
+        {
+            return File.ReadAllBytes(dialog.FileName);
+        }
+        catch (Exception ex)
+        {
+            _notifications.Warning("Couldn't read that image", ex.Message);
+            return null;
+        }
+    }
+
+    private string? AddAsset(byte[] bytes)
+    {
+        try
+        {
+            var image = ImageCache.FromBytes(bytes);
+            var id = _layoutStore.UpsertAsset(bytes, image?.PixelWidth ?? 0, image?.PixelHeight ?? 0);
+            if (id != null && image != null) ImageCache.Put(id, image);
+            return id;
+        }
+        catch (Exception ex)
+        {
+            Debug.WriteLine($"Asset store failed: {ex.Message}");
+            return null;
+        }
+    }
+
+    private void AddImageSource(byte[] bytes)
+    {
+        if (bytes.Length == 0) return;
+        var assetId = AddAsset(bytes);
+        if (assetId != null) AddReusedImage(assetId);
+    }
+
+    private void AddReusedImage(string assetId)
+    {
+        var scene = StagedScene;
+        if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;
+
+        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };
+
+        var image = ImageCache.Get(assetId);
+        if (image != null)
+        {
+            var scale = Math.Min(640.0 / image.PixelWidth, 480.0 / image.PixelHeight);
+            source.Width = image.PixelWidth * scale;
+            source.Height = image.PixelHeight * scale;
+            source.X = (1920 - source.Width) / 2;
+            source.Y = (1080 - source.Height) / 2;
+        }
+
+        scene.Elements.Add(source);
+        SelectedElement = source;
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+
+    // Removes an element from the active scene. For a webcam config this drops the
+    // scene's usage and releases one camera reference (CameraManager stops the
+    // session when the last using scene lets go). When the last config anywhere is
+    // removed, the webcam identity is cleared too — re-adding opens the picker
+    // again instead of silently resurrecting the old camera.
+    private void RemoveElement(SceneElement? element)
+    {
+        var scene = StagedScene;
+        if (scene == null || element == null) return;
+        if (element is Source { IsBackground: true }) return;
+        if (element is WebcamSceneConfig && _webcam != null)
+        {
+            if (SelectedElement == element)
+                SelectedElement = null;
+            _ = _cameraManager.ReleaseAsync(_webcam.DeviceId);
+        }
+        if (element is Source { Type: SourceType.WebSource } webSource)
+            _webView2Manager?.Unregister(webSource.Id);
+        scene.Elements.Remove(element);
+
+        if (element is WebcamSceneConfig && _webcam != null
+            && !Scenes.Any(s => s.Elements.OfType<WebcamSceneConfig>().Any()))
+        {
+            _webcam = null;
+            OnPropertyChanged(nameof(CanChangeWebcam));
+            OnPropertyChanged(nameof(CanAddWebcam));
+            OnPropertyChanged(nameof(CanShowWebcamInStagedScene));
+        }
+
+        OnPropertyChanged(nameof(ShowEmptySceneHint));
+        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
+        UpdateActiveBackground();
+    }
+}

ViewModels/MainViewModel.Streaming.Operations.cs

@@ -0,0 +1,377 @@
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+using Microsoft.Win32;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.Services.Encoder;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+
+    /// <summary>Entry point for the primary Start button (and the start/stop hotkey):
+    /// routes to a record session or the YouTube go-live dialog by the pill state.</summary>
+    private void StartSession()
+    {
+        if (IsLive || IsRecording) return;
+        var streaming = OnAirPillOn;
+        var recording = RecordPillOn;
+        if (!streaming && !recording) return;
+
+        if (!streaming)
+        {
+            BeginRecordOnly();
+            return;
+        }
+        BeginGoLive(recording);
+    }
+
+    /// <summary>Record-only (REC pill on, ON-AIR off): no YouTube dialog — recording
+    /// is local and works signed-out. Generates the auto-named file and starts the
+    /// pipeline immediately.</summary>
+    private async void BeginRecordOnly()
+    {
+        var path = StartRecordFile();
+        if (path == null)
+        {
+            _notifications.Error("Couldn't record", "No record output path could be created.");
+            return;
+        }
+        _recordStartTime = DateTime.Now;
+        _liveElapsed = TimeSpan.Zero;
+        _recordLength = TimeSpan.Zero;
+        ResetHealth(StreamStatus.Offline);
+        _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
+        IsRecording = true;
+        await _framePump.StartAsync();
+    }
+
+    private void BeginGoLive(bool alsoRecord)
+    {
+        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
+        {
+            StreamTitle = BroadcastForm.Title,
+            StreamDescription = BroadcastForm.Description,
+        };
+        var window = new ytLive.GoLiveWindow(dialog) { Owner = System.Windows.Application.Current.MainWindow };
+        if (window.ShowDialog() == true)
+        {
+            StreamTitle = dialog.StreamTitle;
+            StreamDescription = dialog.StreamDescription;
+            StreamVisibility = dialog.Visibility; // always "Private" (ship step 7)
+            BroadcastForm.CaptureGoLive(dialog.StreamTitle, dialog.StreamDescription, DateTime.UtcNow);
+            WindowTitle = string.IsNullOrWhiteSpace(dialog.StreamTitle)
+                ? "LlamaCasty"
+                : $"{dialog.StreamTitle} — LlamaCasty";
+            StreamStatus = StreamStatus.Streaming;
+            ResetHealth(StreamStatus.Streaming);
+            _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
+            _liveElapsed = TimeSpan.Zero;
+            _recordLength = TimeSpan.Zero;
+
+            var recordStarted = false;
+            if (alsoRecord)
+            {
+                if (StartRecordFile() == null)
+                {
+                    _notifications.Error("Couldn't record",
+                        "No record output path could be created — streaming continues without recording.");
+                }
+                else
+                {
+                    _recordStartTime = DateTime.Now;
+                    recordStarted = true;
+                }
+            }
+            IsRecording = recordStarted;
+
+            _ = PrepareAndStartLiveAsync();
+        }
+    }
+
+    /// <summary>Creates the record file (auto-named <c>ty-…-0000.mp4</c> in the record
+    /// folder) and returns its path, or null when the folder can't be prepared.</summary>
+
+    /// <summary>One-click go-live (TASK 5): ensure the reusable stream, create a
+    /// broadcast bound to it, then start the frame pump. The pump reads the RTMP
+    /// URL once at startup (FramePump.StartAsync), so the stream URL must be set
+    /// before the pump starts — hence the ordering here. Failures surface as an
+    /// error health state, never a crash.</summary>
+    private async Task PrepareAndStartLiveAsync()
+    {
+        try
+        {
+            var stream = await _youtubeStream.GetOrCreateReusableStreamAsync();
+            if (stream == null)
+            {
+                AppLog.Write("Reusable stream unavailable; check the OAuth session");
+                _notifications.Error("Couldn't go live",
+                    "The reusable stream is unavailable — check the YouTube sign-in and try again.");
+                StreamStatus = StreamStatus.Error;
+                return;
+            }
+            _reusableStream = stream;
+            _reusableStreamUrl = stream.RtmpUrl;
+            _layoutStore.SaveReusableStream(stream);
+
+            _currentBroadcastId = await _youtubeStream.CreateBroadcast(
+                StreamTitle, StreamDescription, DateTime.UtcNow, stream.Id);
+            if (_currentBroadcastId == null)
+            {
+                AppLog.Write("Broadcast creation failed; check the OAuth session");
+                _notifications.Error("Couldn't go live", "YouTube rejected the broadcast — check the sign-in and try again.");
+                StreamStatus = StreamStatus.Error;
+                return;
+            }
+            AppLog.Write($"Broadcast created: {_currentBroadcastId}");
+            OnPropertyChanged(nameof(CurrentBroadcastId));
+
+            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
+            {
+                BroadcastForm.IsDrawerOpen = true;
+                _notifications.Warning("Complete your broadcast details",
+                    "Your title and description are empty — fill them in from the Text panel on the right.");
+            }
+
+            // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
+            // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
+            // the stream continues without on-panel chat.
+            try
+            {
+                var liveChatId = await _youtubeStream.GetBroadcastLiveChatIdAsync(_currentBroadcastId);
+                if (liveChatId != null)
+                {
+                    _youtubeChat.Start(liveChatId);
+                    AppLog.Write($"Chat polling started: {liveChatId}");
+                }
+                else
+                {
+                    AppLog.Write("Could not retrieve liveChatId; chat polling disabled");
+                }
+            }
+            catch (Exception chatEx)
+            {
+                AppLog.Write($"Chat start failed (non-fatal): {chatEx.Message}");
+            }
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Go-live preparation failed: {ex.Message}");
+            _notifications.Error("Couldn't go live", ex.Message);
+            StreamStatus = StreamStatus.Error;
+            return;
+        }
+
+        await _framePump.StartAsync(); // never throws; failures log + surface via Failed
+
+        // Health polling (TASK 5 item 3): poll immediately, then every 30s while
+        // live. Report-by-exception — a banner appears only on warning/error.
+        _healthPollTimer.Start();
+        _ = PollHealthAsync();
+    }
+
+    private void OnHealthPollTick(object? sender, EventArgs e) => _ = PollHealthAsync();
+
+    /// <summary>One liveStreams.list poll (TASK 5 item 3): updates the YouTube
+    /// health state + the report-by-exception banner. Never throws — a poll
+    /// failure logs and leaves the last state untouched.</summary>
+    private async Task PollHealthAsync()
+    {
+        if (_reusableStream == null || !IsLive) return;
+        try
+        {
+            var health = await _youtubeStream.GetStreamHealthAsync(_reusableStream.Id);
+            if (health == null)
+            {
+                AppLog.Write("Stream health poll failed; check the OAuth session");
+                return;
+            }
+            CurrentHealth.HealthStatus = health.HealthStatus;
+            CurrentHealth.HealthMessage = health.HealthStatus;
+            CurrentHealth.ConfigurationIssues.Clear();
+            CurrentHealth.ConfigurationIssues.AddRange(health.ConfigurationIssues);
+            OnPropertyChanged(nameof(CurrentHealth));
+            ApplyHealthIssue(health.ConfigurationIssues);
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"Stream health poll failed: {ex.Message}");
+        }
+    }
+
+    // Report-by-exception: good/ok/noData (or info-only issues) clear the banner;
+    // the first warning/error issue raises it, colored by the worst severity.
+    private void ApplyHealthIssue(List<StreamConfigurationIssue> issues)
+    {
+        var report = StreamHealthReporter.BannerFor(issues);
+        if (report.Text == null)
+        {
+            HealthIssueBanner = null;
+            HealthIssueBackground = "Transparent";
+            return;
+        }
+
+        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
+        HealthIssueBanner = report.Text;
+    }
+
+    private async void StopStream()
+    {
+        var wasLive = IsLive;
+        var wasRecording = IsRecording;
+
+        StreamStatus = StreamStatus.Offline;
+        IsRecording = false;
+        WindowTitle = "LlamaCasty";
+        ResetHealth(StreamStatus.Offline);
+        // Stop chat polling first (TASK 9.4) — no more messages arriving while
+        // we're tearing down the stream.
+        _youtubeChat.Stop();
+        // Close the audio pipe FIRST so ffmpeg sees EOF on the audio input,
+        // then stop the pump (stdin EOF) — both inputs end and the encoder
+        // finalizes the output. Audio capture itself is always-on (preview
+        // monitoring); only the live/report pipe, the pump, and the session stop here.
+        _audioMixer.StopLive();
+        await _framePump.StopAsync();
+        _currentBroadcastId = null;
+        OnPropertyChanged(nameof(CurrentBroadcastId));
+
+        if (wasRecording) await FinalizeRecordingAsync();
+
+        // Explicit sign-out only (TASK 18): stopping the stream does NOT clear
+        // the session/token — the creator signs out deliberately via the
+        // Logout / Change Account commands.
+        AppLog.Write(wasLive ? "Stream ended" : "Recording ended");
+    }
+
+    /// <summary>On stop the auto-named <c>ty-…-0000.mp4</c> file is renamed to carry
+    /// the real recording length (<c>ty-…-hh2mm2.mp4</c>), with a numeric suffix on
+    /// name collisions. Runs only after the pump has fully closed the file.</summary>
+
+
+
+    /// <summary>Falls back to the user's Downloads folder when no preference is set;
+    /// returns MyVideos if Downloads doesn't exist.</summary>
+
+    // Full encoder options for the current tier, or null when no RTMP URL is
+    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
+    private EncoderOptions? BuildEncoderOptions()
+    {
+        var url = _rtmpUrlProvider();
+        var quality = SelectedQuality;
+        return new EncoderOptions
+        {
+            RtmpUrl = url ?? string.Empty,
+            StreamEnabled = OnAirPillOn,
+            RecordEnabled = RecordPillOn,
+            RecordPath = _activeRecordPath,
+            Width = quality.Width,
+            Height = quality.Height,
+            Fps = quality.Fps,
+            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
+        };
+    }
+
+    private void OnFramePumpFailed(object? sender, string message)
+    {
+        AppLog.Write($"Frame pump failed: {message}");
+        _notifications.Error("The stream pipeline stopped", message);
+        if (IsLive) StreamStatus = StreamStatus.Error;
+    }
+
+    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
+    // duration) lands in the bottom bar. The stderr loop raises on a background
+    // thread — marshal to the UI thread like the audio level handlers.
+    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
+    {
+        var dispatcher = System.Windows.Application.Current?.Dispatcher;
+        if (dispatcher != null && !dispatcher.CheckAccess())
+            dispatcher.BeginInvoke(() => ApplyHealth(health));
+        else
+            ApplyHealth(health);
+    }
+
+    private void ApplyHealth(StreamHealth health)
+    {
+        CurrentHealth.Status = health.Status;
+        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
+        CurrentHealth.FPS = health.FPS;
+        CurrentHealth.DroppedFrames = health.DroppedFrames;
+        CurrentHealth.StreamDuration = health.StreamDuration;
+        CurrentHealth.LastError = health.LastError;
+        CurrentHealth.HealthMessage = health.HealthMessage;
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
+    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
+    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
+    // on the tier's targets — ApplyStreamQuality sets them on pick).
+    private void ResetHealth(StreamStatus status)
+    {
+        CurrentHealth.Status = status;
+        CurrentHealth.DroppedFrames = 0;
+        CurrentHealth.StreamDuration = TimeSpan.Zero;
+        CurrentHealth.LastError = null;
+        CurrentHealth.HealthStatus = null;
+        CurrentHealth.HealthMessage = null;
+        CurrentHealth.ConfigurationIssues.Clear();
+        HealthIssueBanner = null;
+        HealthIssueBackground = "Transparent";
+        OnPropertyChanged(nameof(CurrentHealth));
+    }
+
+    private void UpdateLiveVisuals()
+    {
+        var live = IsLive;
+        TopBarBackground = live ? "#e94560" : "#16213e";
+        PreviewGlowBrush = live ? "#e94560" : "Transparent";
+        PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);
+
+        if (live)
+        {
+            if (BrandFlashEnabled) StartBrandFlashTimer();
+        }
+        else
+        {
+            _healthPollTimer.Stop();
+            _brandFlashTimer.Stop();
+            _brandFlashOffTimer.Stop();
+            BrandFlashActive = false;
+        }
+        UpdateSessionTimer();
+    }
+
+    /// <summary>Runs the elapsed/rec-dot-pulse timer while a session is active —
+    /// live (Streaming) OR recording. Reset the elapsed when a new session starts.</summary>
+    private void UpdateSessionTimer()
+    {
+        var active = IsLive || IsRecording;
+        if (active)
+        {
+            _recDotPulse = 1.0;
+            _liveTimer.Start();
+        }
+        else
+        {
+            _liveTimer.Stop();
+            LiveElapsedText = "00:00:00";
+            _recDotPulse = 1.0;
+        }
+        OnPropertyChanged(nameof(RecDotOpacity));
+        OnPropertyChanged(nameof(LiveElapsedText));
+    }
+
+    private void OnLiveTimerTick(object? sender, EventArgs e)
+    {
+        _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
+        LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
+        _recordLength = _liveElapsed;
+        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
+        OnPropertyChanged(nameof(RecDotOpacity));
+    }
+}

ViewModels/MainViewModel.Streaming.cs

@@ -1,9 +1,7 @@
 using System.Collections.ObjectModel;
-using System.IO;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Threading;
-using Microsoft.Win32;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
@@ -40,14 +38,9 @@ public partial class MainViewModel : ViewModelBase
     private bool _recordPillOn;
     private bool _onAirPillOn;
     private bool _isRecording;
-    private string? _recordFolder;
 
     /// <summary>Resolved record folder — the configured choice, or Downloads (0th case).</summary>
-    public string RecordFolderDisplay => _recordFolder ?? DefaultRecordFolder();
 
-    private string? _activeRecordPath;
-    private DateTime _recordStartTime;
-    private TimeSpan _recordLength;
 
     private readonly FramePump _framePump;
 
@@ -327,463 +320,4 @@ public partial class MainViewModel : ViewModelBase
     public ICommand EndStreamCommand { get; }
     public ICommand ChooseRecordFolderCommand { get; }
     public ICommand ResetRecordFolderCommand { get; }
-
-    /// <summary>Entry point for the primary Start button (and the start/stop hotkey):
-    /// routes to a record session or the YouTube go-live dialog by the pill state.</summary>
-    private void StartSession()
-    {
-        if (IsLive || IsRecording) return;
-        var streaming = OnAirPillOn;
-        var recording = RecordPillOn;
-        if (!streaming && !recording) return;
-
-        if (!streaming)
-        {
-            BeginRecordOnly();
-            return;
-        }
-        BeginGoLive(recording);
-    }
-
-    /// <summary>Record-only (REC pill on, ON-AIR off): no YouTube dialog — recording
-    /// is local and works signed-out. Generates the auto-named file and starts the
-    /// pipeline immediately.</summary>
-    private async void BeginRecordOnly()
-    {
-        var path = StartRecordFile();
-        if (path == null)
-        {
-            _notifications.Error("Couldn't record", "No record output path could be created.");
-            return;
-        }
-        _recordStartTime = DateTime.Now;
-        _liveElapsed = TimeSpan.Zero;
-        _recordLength = TimeSpan.Zero;
-        ResetHealth(StreamStatus.Offline);
-        _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
-        IsRecording = true;
-        await _framePump.StartAsync();
-    }
-
-    private void BeginGoLive(bool alsoRecord)
-    {
-        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
-        {
-            StreamTitle = BroadcastForm.Title,
-            StreamDescription = BroadcastForm.Description,
-        };
-        var window = new ytLive.GoLiveWindow(dialog) { Owner = System.Windows.Application.Current.MainWindow };
-        if (window.ShowDialog() == true)
-        {
-            StreamTitle = dialog.StreamTitle;
-            StreamDescription = dialog.StreamDescription;
-            StreamVisibility = dialog.Visibility; // always "Private" (ship step 7)
-            BroadcastForm.CaptureGoLive(dialog.StreamTitle, dialog.StreamDescription, DateTime.UtcNow);
-            WindowTitle = string.IsNullOrWhiteSpace(dialog.StreamTitle)
-                ? "LlamaCasty"
-                : $"{dialog.StreamTitle} — LlamaCasty";
-            StreamStatus = StreamStatus.Streaming;
-            ResetHealth(StreamStatus.Streaming);
-            _audioMixer.StartLive(EncoderOptions.DefaultAudioPipeName);
-            _liveElapsed = TimeSpan.Zero;
-            _recordLength = TimeSpan.Zero;
-
-            var recordStarted = false;
-            if (alsoRecord)
-            {
-                if (StartRecordFile() == null)
-                {
-                    _notifications.Error("Couldn't record",
-                        "No record output path could be created — streaming continues without recording.");
-                }
-                else
-                {
-                    _recordStartTime = DateTime.Now;
-                    recordStarted = true;
-                }
-            }
-            IsRecording = recordStarted;
-
-            _ = PrepareAndStartLiveAsync();
-        }
-    }
-
-    /// <summary>Creates the record file (auto-named <c>ty-…-0000.mp4</c> in the record
-    /// folder) and returns its path, or null when the folder can't be prepared.</summary>
-    private string? StartRecordFile()
-    {
-        try
-        {
-            var folder = _recordFolder ?? DefaultRecordFolder();
-            Directory.CreateDirectory(folder);
-            var name = RecordingFile.BuildStartName(DateTime.Now) + ".mp4";
-            var path = Path.Combine(folder, name);
-            _activeRecordPath = path;
-            return path;
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write(ex, "Recording: failed to prepare output path");
-            return null;
-        }
-    }
-
-    /// <summary>One-click go-live (TASK 5): ensure the reusable stream, create a
-    /// broadcast bound to it, then start the frame pump. The pump reads the RTMP
-    /// URL once at startup (FramePump.StartAsync), so the stream URL must be set
-    /// before the pump starts — hence the ordering here. Failures surface as an
-    /// error health state, never a crash.</summary>
-    private async Task PrepareAndStartLiveAsync()
-    {
-        try
-        {
-            var stream = await _youtubeStream.GetOrCreateReusableStreamAsync();
-            if (stream == null)
-            {
-                AppLog.Write("Reusable stream unavailable; check the OAuth session");
-                _notifications.Error("Couldn't go live",
-                    "The reusable stream is unavailable — check the YouTube sign-in and try again.");
-                StreamStatus = StreamStatus.Error;
-                return;
-            }
-            _reusableStream = stream;
-            _reusableStreamUrl = stream.RtmpUrl;
-            _layoutStore.SaveReusableStream(stream);
-
-            _currentBroadcastId = await _youtubeStream.CreateBroadcast(
-                StreamTitle, StreamDescription, DateTime.UtcNow, stream.Id);
-            if (_currentBroadcastId == null)
-            {
-                AppLog.Write("Broadcast creation failed; check the OAuth session");
-                _notifications.Error("Couldn't go live", "YouTube rejected the broadcast — check the sign-in and try again.");
-                StreamStatus = StreamStatus.Error;
-                return;
-            }
-            AppLog.Write($"Broadcast created: {_currentBroadcastId}");
-            OnPropertyChanged(nameof(CurrentBroadcastId));
-
-            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
-            {
-                BroadcastForm.IsDrawerOpen = true;
-                _notifications.Warning("Complete your broadcast details",
-                    "Your title and description are empty — fill them in from the Text panel on the right.");
-            }
-
-            // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
-            // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
-            // the stream continues without on-panel chat.
-            try
-            {
-                var liveChatId = await _youtubeStream.GetBroadcastLiveChatIdAsync(_currentBroadcastId);
-                if (liveChatId != null)
-                {
-                    _youtubeChat.Start(liveChatId);
-                    AppLog.Write($"Chat polling started: {liveChatId}");
-                }
-                else
-                {
-                    AppLog.Write("Could not retrieve liveChatId; chat polling disabled");
-                }
-            }
-            catch (Exception chatEx)
-            {
-                AppLog.Write($"Chat start failed (non-fatal): {chatEx.Message}");
-            }
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write($"Go-live preparation failed: {ex.Message}");
-            _notifications.Error("Couldn't go live", ex.Message);
-            StreamStatus = StreamStatus.Error;
-            return;
-        }
-
-        await _framePump.StartAsync(); // never throws; failures log + surface via Failed
-
-        // Health polling (TASK 5 item 3): poll immediately, then every 30s while
-        // live. Report-by-exception — a banner appears only on warning/error.
-        _healthPollTimer.Start();
-        _ = PollHealthAsync();
-    }
-
-    private void OnHealthPollTick(object? sender, EventArgs e) => _ = PollHealthAsync();
-
-    /// <summary>One liveStreams.list poll (TASK 5 item 3): updates the YouTube
-    /// health state + the report-by-exception banner. Never throws — a poll
-    /// failure logs and leaves the last state untouched.</summary>
-    private async Task PollHealthAsync()
-    {
-        if (_reusableStream == null || !IsLive) return;
-        try
-        {
-            var health = await _youtubeStream.GetStreamHealthAsync(_reusableStream.Id);
-            if (health == null)
-            {
-                AppLog.Write("Stream health poll failed; check the OAuth session");
-                return;
-            }
-            CurrentHealth.HealthStatus = health.HealthStatus;
-            CurrentHealth.HealthMessage = health.HealthStatus;
-            CurrentHealth.ConfigurationIssues.Clear();
-            CurrentHealth.ConfigurationIssues.AddRange(health.ConfigurationIssues);
-            OnPropertyChanged(nameof(CurrentHealth));
-            ApplyHealthIssue(health.ConfigurationIssues);
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write($"Stream health poll failed: {ex.Message}");
-        }
-    }
-
-    // Report-by-exception: good/ok/noData (or info-only issues) clear the banner;
-    // the first warning/error issue raises it, colored by the worst severity.
-    private void ApplyHealthIssue(List<StreamConfigurationIssue> issues)
-    {
-        var report = StreamHealthReporter.BannerFor(issues);
-        if (report.Text == null)
-        {
-            HealthIssueBanner = null;
-            HealthIssueBackground = "Transparent";
-            return;
-        }
-
-        HealthIssueBackground = report.IsError ? "#8f1f1f" : "#b8860b";
-        HealthIssueBanner = report.Text;
-    }
-
-    private async void StopStream()
-    {
-        var wasLive = IsLive;
-        var wasRecording = IsRecording;
-
-        StreamStatus = StreamStatus.Offline;
-        IsRecording = false;
-        WindowTitle = "LlamaCasty";
-        ResetHealth(StreamStatus.Offline);
-        // Stop chat polling first (TASK 9.4) — no more messages arriving while
-        // we're tearing down the stream.
-        _youtubeChat.Stop();
-        // Close the audio pipe FIRST so ffmpeg sees EOF on the audio input,
-        // then stop the pump (stdin EOF) — both inputs end and the encoder
-        // finalizes the output. Audio capture itself is always-on (preview
-        // monitoring); only the live/report pipe, the pump, and the session stop here.
-        _audioMixer.StopLive();
-        await _framePump.StopAsync();
-        _currentBroadcastId = null;
-        OnPropertyChanged(nameof(CurrentBroadcastId));
-
-        if (wasRecording) await FinalizeRecordingAsync();
-
-        // Explicit sign-out only (TASK 18): stopping the stream does NOT clear
-        // the session/token — the creator signs out deliberately via the
-        // Logout / Change Account commands.
-        AppLog.Write(wasLive ? "Stream ended" : "Recording ended");
-    }
-
-    /// <summary>On stop the auto-named <c>ty-…-0000.mp4</c> file is renamed to carry
-    /// the real recording length (<c>ty-…-hh2mm2.mp4</c>), with a numeric suffix on
-    /// name collisions. Runs only after the pump has fully closed the file.</summary>
-    private async Task FinalizeRecordingAsync()
-    {
-        var startPath = _activeRecordPath;
-        _activeRecordPath = null;
-        if (string.IsNullOrEmpty(startPath)) return;
-        try
-        {
-            while (_framePump.IsRunning) await Task.Delay(50);
-
-            if (!File.Exists(startPath))
-            {
-                AppLog.Write($"Recording: output not found for rename: {startPath}");
-                return;
-            }
-            _recordLength = _liveElapsed;
-            var autoStem = RecordingFile.BuildFinalName(_recordStartTime, _recordLength);
-            var dir = Path.GetDirectoryName(startPath)!;
-
-            // Manual rename modal: give the creator a chance to name the recording;
-            // null = keep the auto name (or the default recorded above).
-            string stem = autoStem;
-            var dialog = new RenameRecordingDialog(autoStem);
-            if (dialog.ShowDialog() == true && !string.IsNullOrEmpty(dialog.ResultFileName))
-                stem = dialog.ResultFileName;
-
-            var finalPath = UniquePath(Path.Combine(dir, stem + ".mp4"));
-            File.Move(startPath, finalPath);
-            AppLog.Write($"Recording saved: {finalPath}");
-            _notifications.Info("Recording saved",
-                Path.GetFileName(finalPath) + " — you can rename it in your videos folder at any time.");
-        }
-        catch (Exception ex)
-        {
-            AppLog.Write(ex, "Recording: rename-on-stop failed");
-            _notifications.Error("Recording saved",
-                $"The recording was written but couldn't be renamed: {Path.GetFileName(startPath)}");
-        }
-    }
-
-    private static string UniquePath(string path)
-    {
-        if (!File.Exists(path)) return path;
-        var dir = Path.GetDirectoryName(path)!;
-        var name = Path.GetFileNameWithoutExtension(path);
-        var ext = Path.GetExtension(path);
-        for (var i = 2; ; i++)
-        {
-            var candidate = Path.Combine(dir, $"{name}-{i}{ext}");
-            if (!File.Exists(candidate)) return candidate;
-        }
-    }
-
-    private void ChooseRecordFolder()
-    {
-        var dialog = new Microsoft.Win32.OpenFolderDialog
-        {
-            Title = "Choose a folder for local recordings",
-            InitialDirectory = _recordFolder ?? DefaultRecordFolder(),
-        };
-        if (dialog.ShowDialog() == true)
-        {
-            _recordFolder = dialog.FolderName;
-            _layoutStore.SaveRecordFolder(_recordFolder);
-            OnPropertyChanged(nameof(RecordFolderDisplay));
-            _notifications.Info("Record folder set", _recordFolder);
-        }
-    }
-
-    private void ResetRecordFolder()
-    {
-        _recordFolder = null;
-        _layoutStore.SaveRecordFolder(null);
-        OnPropertyChanged(nameof(RecordFolderDisplay));
-        _notifications.Info("Record folder reset", RecordFolderDisplay);
-    }
-
-    /// <summary>Falls back to the user's Downloads folder when no preference is set;
-    /// returns MyVideos if Downloads doesn't exist.</summary>
-    internal static string DefaultRecordFolder()
-    {
-        var downloads = Path.Combine(
-            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Downloads");
-        return Directory.Exists(downloads)
-            ? downloads
-            : Environment.GetFolderPath(Environment.SpecialFolder.MyVideos);
-    }
-
-    // Full encoder options for the current tier, or null when no RTMP URL is
-    // available — the pump then skips the encoder entirely (TASK 5 fills the seam).
-    private EncoderOptions? BuildEncoderOptions()
-    {
-        var url = _rtmpUrlProvider();
-        var quality = SelectedQuality;
-        return new EncoderOptions
-        {
-            RtmpUrl = url ?? string.Empty,
-            StreamEnabled = OnAirPillOn,
-            RecordEnabled = RecordPillOn,
-            RecordPath = _activeRecordPath,
-            Width = quality.Width,
-            Height = quality.Height,
-            Fps = quality.Fps,
-            BitrateKbps = (int)Math.Round(quality.Bitrate * 1000),
-        };
-    }
-
-    private void OnFramePumpFailed(object? sender, string message)
-    {
-        AppLog.Write($"Frame pump failed: {message}");
-        _notifications.Error("The stream pipeline stopped", message);
-        if (IsLive) StreamStatus = StreamStatus.Error;
-    }
-
-    // TASK 4 ship step 6: the encoder's parsed health (bitrate/FPS/dropped/
-    // duration) lands in the bottom bar. The stderr loop raises on a background
-    // thread — marshal to the UI thread like the audio level handlers.
-    private void OnFramePumpHealthUpdated(object? sender, StreamHealth health)
-    {
-        var dispatcher = System.Windows.Application.Current?.Dispatcher;
-        if (dispatcher != null && !dispatcher.CheckAccess())
-            dispatcher.BeginInvoke(() => ApplyHealth(health));
-        else
-            ApplyHealth(health);
-    }
-
-    private void ApplyHealth(StreamHealth health)
-    {
-        CurrentHealth.Status = health.Status;
-        CurrentHealth.CurrentBitrate = health.CurrentBitrate;
-        CurrentHealth.FPS = health.FPS;
-        CurrentHealth.DroppedFrames = health.DroppedFrames;
-        CurrentHealth.StreamDuration = health.StreamDuration;
-        CurrentHealth.LastError = health.LastError;
-        CurrentHealth.HealthMessage = health.HealthMessage;
-        OnPropertyChanged(nameof(CurrentHealth));
-    }
-
-    // Keeps the bottom-bar stats honest across sessions: dropped frames and the
-    // elapsed duration must not linger from a previous go-live (bitrate/FPS stay
-    // on the tier's targets — ApplyStreamQuality sets them on pick).
-    private void ResetHealth(StreamStatus status)
-    {
-        CurrentHealth.Status = status;
-        CurrentHealth.DroppedFrames = 0;
-        CurrentHealth.StreamDuration = TimeSpan.Zero;
-        CurrentHealth.LastError = null;
-        CurrentHealth.HealthStatus = null;
-        CurrentHealth.HealthMessage = null;
-        CurrentHealth.ConfigurationIssues.Clear();
-        HealthIssueBanner = null;
-        HealthIssueBackground = "Transparent";
-        OnPropertyChanged(nameof(CurrentHealth));
-    }
-
-    private void UpdateLiveVisuals()
-    {
-        var live = IsLive;
-        TopBarBackground = live ? "#e94560" : "#16213e";
-        PreviewGlowBrush = live ? "#e94560" : "Transparent";
-        PreviewGlowThickness = live ? new Thickness(3) : new Thickness(0);
-
-        if (live)
-        {
-            if (BrandFlashEnabled) StartBrandFlashTimer();
-        }
-        else
-        {
-            _healthPollTimer.Stop();
-            _brandFlashTimer.Stop();
-            _brandFlashOffTimer.Stop();
-            BrandFlashActive = false;
-        }
-        UpdateSessionTimer();
-    }
-
-    /// <summary>Runs the elapsed/rec-dot-pulse timer while a session is active —
-    /// live (Streaming) OR recording. Reset the elapsed when a new session starts.</summary>
-    private void UpdateSessionTimer()
-    {
-        var active = IsLive || IsRecording;
-        if (active)
-        {
-            _recDotPulse = 1.0;
-            _liveTimer.Start();
-        }
-        else
-        {
-            _liveTimer.Stop();
-            LiveElapsedText = "00:00:00";
-            _recDotPulse = 1.0;
-        }
-        OnPropertyChanged(nameof(RecDotOpacity));
-        OnPropertyChanged(nameof(LiveElapsedText));
-    }
-
-    private void OnLiveTimerTick(object? sender, EventArgs e)
-    {
-        _liveElapsed = _liveElapsed.Add(TimeSpan.FromSeconds(1));
-        LiveElapsedText = _liveElapsed.ToString(@"hh\:mm\:ss");
-        _recordLength = _liveElapsed;
-        _recDotPulse = _recDotPulse > 0.5 ? 0.35 : 1.0;
-        OnPropertyChanged(nameof(RecDotOpacity));
-    }
 }

ViewModels/MainViewModel.Web.cs

@@ -0,0 +1,41 @@
+using System.Linq;
+using System.Windows.Controls;
+using System.Windows.Media.Imaging;
+using ytLive.Models;
+using ytLive.Services;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private void RegisterLoadedWebSources()
+    {
+        if (_webView2Manager == null) return;
+
+        foreach (var source in Scenes.SelectMany(s => s.Elements).OfType<Source>()
+                     .Where(s => s.Type == SourceType.WebSource))
+        {
+            _webView2Manager.Register(source);
+            source.PropertyChanged += (_, e) =>
+            {
+                if (e.PropertyName == nameof(Source.WebUri))
+                    _webView2Manager.OnWebUriChanged(source);
+            };
+        }
+    }
+
+    public void InitWebView2(Panel hostPanel)
+    {
+        _webView2Manager = new WebView2Manager(hostPanel, System.Windows.Application.Current.Dispatcher);
+        _webView2Manager.PreviewBitmapChanged += OnWebView2PreviewBitmapChanged;
+        RegisterLoadedWebSources();
+    }
+
+    private void OnWebView2PreviewBitmapChanged(string sourceId, WriteableBitmap bitmap)
+    {
+        foreach (var scene in Scenes)
+            foreach (var el in scene.Elements.OfType<Source>().Where(s => s.Id == sourceId))
+                el.VideoImageSource = bitmap;
+    }
+}

ViewModels/MainViewModel.cs

@@ -1,5 +1,3 @@
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.IO;
@@ -8,10 +6,7 @@ using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Interop;
 using System.Windows.Media;
-using System.Windows.Media.Imaging;
 using System.Windows.Threading;
-using Microsoft.Win32;
-using NAudio.CoreAudioApi;
 using ytLive.Helpers;
 using ytLive.Models;
 using ytLive.Services;
@@ -279,7 +274,7 @@ public partial class MainViewModel : ViewModelBase
         _screenCaptureManager.CaptureFailed += (key, message) =>
             AppLog.Write($"ScreenCaptureManager: capture '{key}' failed: {message}");
 
-        _chatBoxRenderer = new ChatBoxRenderer();
+        _chatLayer = new ChatOverlayLayer(new ChatBoxRenderer());
 
         _rtmpUrlProvider = () => _reusableStreamUrl; // TASK 5: the reusable stream's ingest URL
         _framePump = new FramePump(
@@ -383,35 +378,6 @@ public partial class MainViewModel : ViewModelBase
         AppLog.Write("LoadLayout end");
     }
 
-    private void RegisterLoadedWebSources()
-    {
-        if (_webView2Manager == null) return;
-
-        foreach (var source in Scenes.SelectMany(s => s.Elements).OfType<Source>()
-                     .Where(s => s.Type == SourceType.WebSource))
-        {
-            _webView2Manager.Register(source);
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName == nameof(Source.WebUri))
-                    _webView2Manager.OnWebUriChanged(source);
-            };
-        }
-    }
-
-    public void InitWebView2(Panel hostPanel)
-    {
-        _webView2Manager = new WebView2Manager(hostPanel, System.Windows.Application.Current.Dispatcher);
-        _webView2Manager.PreviewBitmapChanged += OnWebView2PreviewBitmapChanged;
-        RegisterLoadedWebSources();
-    }
-
-    private void OnWebView2PreviewBitmapChanged(string sourceId, WriteableBitmap bitmap)
-    {
-        foreach (var scene in Scenes)
-            foreach (var el in scene.Elements.OfType<Source>().Where(s => s.Id == sourceId))
-                el.VideoImageSource = bitmap;
-    }
 
     public void Shutdown()
     {
@@ -463,240 +429,6 @@ public partial class MainViewModel : ViewModelBase
             OnPropertyChanged(nameof(BackgroundVisible));
     }
 
-    private void AddSource(object? parameter)
-    {
-        var scene = StagedScene;
-        if (scene == null) return;
-
-        var sourceType = parameter is SourceType typed
-            ? typed
-            : Enum.TryParse<SourceType>(parameter?.ToString(), true, out var parsed) ? parsed : SourceType.Image;
-        var baseName = sourceType switch
-        {
-            SourceType.Image => "Image",
-            SourceType.TextOverlay => "Text",
-            SourceType.Countdown => "Countdown",
-            SourceType.WebSource => "Web Resource",
-            SourceType.ChatBox => "YouTube Chat",
-            _ => "Layer",
-        };
-
-        // The (+) menu only adds regular layers. The Background is a locked
-        // per-screen layer managed by EnsureBackground/NormalizeBackgrounds —
-        // never user-created, never deleted. YouTube Chat is one-per-layout.
-        if (sourceType is SourceType.DisplayCapture or SourceType.WindowCapture or SourceType.Background)
-            return;
-        if (sourceType == SourceType.ChatBox && !CanAddYouTubeChat)
-            return;
-
-        // Web resources use "Web Resource-N" naming (0-indexed per scene)
-        var webCount = scene.Elements.OfType<Source>().Count(s => s.Type == SourceType.WebSource);
-        var source = new Source
-        {
-            Name = sourceType == SourceType.WebSource
-                ? $"{baseName}-{webCount}"
-                : NextSourceName(scene, baseName),
-            Type = sourceType,
-            X = sourceType == SourceType.ChatBox ? 1400 : 0,
-            Y = sourceType == SourceType.ChatBox ? 20 : 0,
-            Width = sourceType == SourceType.WebSource ? 640 : sourceType == SourceType.ChatBox ? 500 : 0,
-            Height = sourceType == SourceType.WebSource ? 480 : sourceType == SourceType.ChatBox ? 648 : 0,
-        };
-        scene.Elements.Add(source);
-
-        if (sourceType == SourceType.WebSource)
-        {
-            _webView2Manager?.Register(source);
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName == nameof(Source.WebUri))
-                    _webView2Manager?.OnWebUriChanged(source);
-            };
-        }
-
-        if (sourceType == SourceType.ChatBox)
-        {
-            source.PropertyChanged += (_, e) =>
-            {
-                if (e.PropertyName is nameof(Source.ChatFontSize) or nameof(Source.ChatFontColor)
-                    or nameof(Source.ChatBackgroundColor) or nameof(Source.ChatBackgroundOpacity)
-                    or nameof(Source.ChatMaxMessages) or nameof(Source.ChatShowTimestamps)
-                    or nameof(Source.ChatShowBadges) or nameof(Source.ChatMemberColor)
-                    or nameof(Source.ChatSuperChatColor) or nameof(Source.ChatFontFamily)
-                    or nameof(Source.ChatFadeSeconds) or nameof(Source.Width) or nameof(Source.Height))
-                    UpdateChatBoxPreview(source);
-            };
-            UpdateChatBoxPreview(source);
-        }
-
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
-
-    // Duplicate resource names get an incrementing suffix with no space: Image,
-    // Image2, Image3… The next free number is derived from the names actually in
-    // the scene, so deleting a middle resource never collides with a survivor.
-    private static string NextSourceName(Scene scene, string baseName)
-    {
-        var taken = scene.Elements.OfType<Source>()
-            .Select(s => s.Name)
-            .Where(n => string.Equals(n, baseName, StringComparison.OrdinalIgnoreCase)
-                || (n.Length > baseName.Length
-                    && n.StartsWith(baseName, StringComparison.OrdinalIgnoreCase)
-                    && int.TryParse(n.Substring(baseName.Length), out _)))
-            .ToHashSet(StringComparer.OrdinalIgnoreCase);
-        if (!taken.Contains(baseName)) return baseName;
-        for (var i = 2; ; i++)
-            if (!taken.Contains($"{baseName}{i}"))
-                return $"{baseName}{i}";
-    }
-
-    private void AddImage()
-    {
-        var scene = StagedScene;
-        if (scene == null) return;
-
-        var candidates = BuildImageCandidates();
-        if (candidates.Count == 0)
-        {
-            var bytes = PickImageBytes("Choose an image");
-            if (bytes != null) AddImageSource(bytes);
-            return;
-        }
-
-        var dialog = new ReuseImageDialog(new ReuseImageViewModel(candidates))
-        {
-            Owner = Application.Current.MainWindow
-        };
-        if (dialog.ShowDialog() != true) return;
-
-        if (dialog.WantsNew)
-        {
-            var bytes = PickImageBytes("Choose an image");
-            if (bytes != null) AddImageSource(bytes);
-        }
-        else
-        {
-            AddReusedImage(dialog.PickedAssetId!);
-        }
-    }
-
-    private List<ReuseImageCandidate> BuildImageCandidates()
-    {
-        var candidates = new List<ReuseImageCandidate>();
-        foreach (var scene in Scenes)
-        foreach (var source in scene.Elements.OfType<Source>().Where(s => s.Type == SourceType.Image && !string.IsNullOrWhiteSpace(s.AssetId)))
-        {
-            candidates.Add(new ReuseImageCandidate
-            {
-                SceneName = scene.Name,
-                SourceName = source.Name,
-                AssetId = source.AssetId!
-            });
-        }
-        return candidates;
-    }
-
-    private byte[]? PickImageBytes(string title)
-    {
-        var dialog = new OpenFileDialog
-        {
-            Title = title,
-            Filter = "Image files (*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp)|*.png;*.jpg;*.jpeg;*.bmp;*.gif;*.webp|All files (*.*)|*.*"
-        };
-        if (dialog.ShowDialog() != true) return null;
-        try
-        {
-            return File.ReadAllBytes(dialog.FileName);
-        }
-        catch (Exception ex)
-        {
-            _notifications.Warning("Couldn't read that image", ex.Message);
-            return null;
-        }
-    }
-
-    private string? AddAsset(byte[] bytes)
-    {
-        try
-        {
-            var image = ImageCache.FromBytes(bytes);
-            var id = _layoutStore.UpsertAsset(bytes, image?.PixelWidth ?? 0, image?.PixelHeight ?? 0);
-            if (id != null && image != null) ImageCache.Put(id, image);
-            return id;
-        }
-        catch (Exception ex)
-        {
-            Debug.WriteLine($"Asset store failed: {ex.Message}");
-            return null;
-        }
-    }
-
-    private void AddImageSource(byte[] bytes)
-    {
-        if (bytes.Length == 0) return;
-        var assetId = AddAsset(bytes);
-        if (assetId != null) AddReusedImage(assetId);
-    }
-
-    private void AddReusedImage(string assetId)
-    {
-        var scene = StagedScene;
-        if (scene == null || string.IsNullOrWhiteSpace(assetId)) return;
-
-        var source = new Source { Name = NextSourceName(scene, "Image"), Type = SourceType.Image, AssetId = assetId };
-
-        var image = ImageCache.Get(assetId);
-        if (image != null)
-        {
-            var scale = Math.Min(640.0 / image.PixelWidth, 480.0 / image.PixelHeight);
-            source.Width = image.PixelWidth * scale;
-            source.Height = image.PixelHeight * scale;
-            source.X = (1920 - source.Width) / 2;
-            source.Y = (1080 - source.Height) / 2;
-        }
-
-        scene.Elements.Add(source);
-        SelectedElement = source;
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
-
-    // Removes an element from the active scene. For a webcam config this drops the
-    // scene's usage and releases one camera reference (CameraManager stops the
-    // session when the last using scene lets go). When the last config anywhere is
-    // removed, the webcam identity is cleared too — re-adding opens the picker
-    // again instead of silently resurrecting the old camera.
-    private void RemoveElement(SceneElement? element)
-    {
-        var scene = StagedScene;
-        if (scene == null || element == null) return;
-        if (element is Source { IsBackground: true }) return;
-        if (element is WebcamSceneConfig && _webcam != null)
-        {
-            if (SelectedElement == element)
-                SelectedElement = null;
-            _ = _cameraManager.ReleaseAsync(_webcam.DeviceId);
-        }
-        if (element is Source { Type: SourceType.WebSource } webSource)
-            _webView2Manager?.Unregister(webSource.Id);
-        scene.Elements.Remove(element);
-
-        if (element is WebcamSceneConfig && _webcam != null
-            && !Scenes.Any(s => s.Elements.OfType<WebcamSceneConfig>().Any()))
-        {
-            _webcam = null;
-            OnPropertyChanged(nameof(CanChangeWebcam));
-            OnPropertyChanged(nameof(CanAddWebcam));
-            OnPropertyChanged(nameof(CanShowWebcamInStagedScene));
-        }
-
-        OnPropertyChanged(nameof(ShowEmptySceneHint));
-        OnPropertyChanged(nameof(ShowSourcesEmptyHint));
-        UpdateActiveBackground();
-    }
 
     // Scene-element → latest frame, for the live compositor. The map mirrors the
     // preview: webcam by DeviceId, live captures (the background) by CaptureKey,

ViewModels/SocialSlotViewModel.cs

@@ -0,0 +1,183 @@
+using System.ComponentModel;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.ViewModels;
+
+namespace ytLive.ViewModels;
+public sealed record DialogEntry(SocialService Service, string Handle, string ProfileUrl, string? FediverseSoftware = null);
+
+/// <summary>
+/// One of the six fixed dialog rows. Row 0 is always YouTube (signed-in account
+/// or a sign-in prompt); rows 1-5 hold validated entries, an empty slot, or — on
+/// the free tier — a locked "Premium" slot. Rows are a positional projection of
+/// the dialog's working list, so deleting an entry makes the ones above advance up.
+/// </summary>
+public sealed class SocialSlotViewModel : ViewModelBase
+{
+    public int Index { get; }
+    public bool IsYoutube => Index == 0;
+
+    private SocialService _service = SocialService.Link;
+    public SocialService Service
+    {
+        get => _service;
+        set { if (SetProperty(ref _service, value)) OnPropertyChanged(nameof(LogoData)); }
+    }
+
+    public string LogoData => Service == SocialService.Fediverse
+        ? SocialServiceIcons.LogoDataForFediverse(FediverseSoftware)
+        : SocialServiceIcons.LogoDataFor(Service);
+    public string LockedIconData => SocialServiceIcons.LockedIconData;
+    public string DoNotIconData => SocialServiceIcons.DoNotIconData;
+
+    private bool _isLocked;
+    public bool IsLocked
+    {
+        get => _isLocked;
+        set
+        {
+            if (SetProperty(ref _isLocked, value))
+            {
+                OnPropertyChanged(nameof(ShowAddButton));
+                OnPropertyChanged(nameof(ShowDoNot));
+                OnPropertyChanged(nameof(DisplayText));
+            }
+        }
+    }
+
+    private bool _isFilled;
+    public bool IsFilled
+    {
+        get => _isFilled;
+        set
+        {
+            if (SetProperty(ref _isFilled, value))
+            {
+                OnPropertyChanged(nameof(ShowEditButton));
+                OnPropertyChanged(nameof(ShowDeleteButton));
+                OnPropertyChanged(nameof(ShowAddButton));
+                OnPropertyChanged(nameof(ShowDoNot));
+                OnPropertyChanged(nameof(DisplayText));
+            }
+        }
+    }
+
+    private bool _isSignIn;
+    public bool IsSignIn
+    {
+        get => _isSignIn;
+        set
+        {
+            if (SetProperty(ref _isSignIn, value))
+            {
+                OnPropertyChanged(nameof(ShowSignInButton));
+                OnPropertyChanged(nameof(ShowDeleteButton));
+                OnPropertyChanged(nameof(ShowLogo));
+                OnPropertyChanged(nameof(DisplayText));
+            }
+        }
+    }
+
+    private bool _isEditing;
+    public bool IsEditing
+    {
+        get => _isEditing;
+        set
+        {
+            if (SetProperty(ref _isEditing, value))
+            {
+                OnPropertyChanged(nameof(ShowEditBox));
+                OnPropertyChanged(nameof(ShowDisplay));
+                OnPropertyChanged(nameof(ShowEditButton));
+                OnPropertyChanged(nameof(ShowDeleteButton));
+                OnPropertyChanged(nameof(ShowAddButton));
+                OnPropertyChanged(nameof(ShowDoNot));
+            }
+        }
+    }
+
+    private bool _isValidating;
+    public bool IsValidating
+    {
+        get => _isValidating;
+        set
+        {
+            if (SetProperty(ref _isValidating, value))
+            {
+                OnPropertyChanged(nameof(ShowBusy));
+                OnPropertyChanged(nameof(ShowDoNot));
+            }
+        }
+    }
+
+    private string _handle = string.Empty;
+    public string Handle
+    {
+        get => _handle;
+        set
+        {
+            if (SetProperty(ref _handle, value))
+                OnPropertyChanged(nameof(DisplayText));
+        }
+    }
+
+    private string? _fediverseSoftware;
+    public string? FediverseSoftware
+    {
+        get => _fediverseSoftware;
+        set
+        {
+            if (SetProperty(ref _fediverseSoftware, value))
+                OnPropertyChanged(nameof(LogoData));
+        }
+    }
+
+    public string ProfileUrl { get; set; } = string.Empty;
+
+    private string? _error;
+    public string? Error
+    {
+        get => _error;
+        set
+        {
+            if (SetProperty(ref _error, value))
+            {
+                OnPropertyChanged(nameof(HasError));
+                OnPropertyChanged(nameof(ShowError));
+                OnPropertyChanged(nameof(ShowDoNot));
+            }
+        }
+    }
+
+    private string _editText = string.Empty;
+    public string EditText
+    {
+        get => _editText;
+        set => SetProperty(ref _editText, value);
+    }
+
+    /// <summary>The last text submitted for validation (used to skip re-validating
+    /// identical input — e.g. a LostFocus firing as the user clicks Cancel).</summary>
+    public string? LastValidatedInput { get; set; }
+
+    public string DisplayText =>
+        IsYoutube
+            ? (IsSignIn ? "Sign in to YouTube" : Handle)
+            : IsLocked ? "Unlock with Premium"
+            : IsFilled ? Handle
+            : "No social yet";
+
+    public bool HasError => !string.IsNullOrEmpty(Error);
+    public bool ShowError => HasError;
+    public bool ShowLogo => IsYoutube ? !IsSignIn : IsFilled;
+    public bool ShowBusy => IsValidating;
+    public bool ShowEditBox => IsEditing;
+    public bool ShowDisplay => !IsEditing && !IsValidating;
+    public bool ShowSignInButton => IsYoutube && IsSignIn && !IsValidating;
+    public bool ShowAddButton => !IsYoutube && !IsLocked && !IsFilled && !IsEditing && !IsValidating;
+    public bool ShowEditButton => !IsYoutube && IsFilled && !IsEditing && !IsValidating;
+    public bool ShowDeleteButton => (IsFilled || IsYoutube) && !IsEditing && !IsValidating;
+    public bool ShowDoNot => !IsYoutube && !IsLocked && (!IsFilled || HasError || IsValidating);
+
+    public SocialSlotViewModel(int index) => Index = index;
+}

ViewModels/SocialsDialogViewModel.cs

@@ -8,187 +8,6 @@ using ytLive.Services;
 
 namespace ytLive.ViewModels;
 
-/// <summary>
-/// A validated social entry in the dialog's working copy (non-YouTube slots).
-/// </summary>
-public sealed record DialogEntry(SocialService Service, string Handle, string ProfileUrl, string? FediverseSoftware = null);
-
-/// <summary>
-/// One of the six fixed dialog rows. Row 0 is always YouTube (signed-in account
-/// or a sign-in prompt); rows 1-5 hold validated entries, an empty slot, or — on
-/// the free tier — a locked "Premium" slot. Rows are a positional projection of
-/// the dialog's working list, so deleting an entry makes the ones above advance up.
-/// </summary>
-public sealed class SocialSlotViewModel : ViewModelBase
-{
-    public int Index { get; }
-    public bool IsYoutube => Index == 0;
-
-    private SocialService _service = SocialService.Link;
-    public SocialService Service
-    {
-        get => _service;
-        set { if (SetProperty(ref _service, value)) OnPropertyChanged(nameof(LogoData)); }
-    }
-
-    public string LogoData => Service == SocialService.Fediverse
-        ? SocialServiceIcons.LogoDataForFediverse(FediverseSoftware)
-        : SocialServiceIcons.LogoDataFor(Service);
-    public string LockedIconData => SocialServiceIcons.LockedIconData;
-    public string DoNotIconData => SocialServiceIcons.DoNotIconData;
-
-    private bool _isLocked;
-    public bool IsLocked
-    {
-        get => _isLocked;
-        set
-        {
-            if (SetProperty(ref _isLocked, value))
-            {
-                OnPropertyChanged(nameof(ShowAddButton));
-                OnPropertyChanged(nameof(ShowDoNot));
-                OnPropertyChanged(nameof(DisplayText));
-            }
-        }
-    }
-
-    private bool _isFilled;
-    public bool IsFilled
-    {
-        get => _isFilled;
-        set
-        {
-            if (SetProperty(ref _isFilled, value))
-            {
-                OnPropertyChanged(nameof(ShowEditButton));
-                OnPropertyChanged(nameof(ShowDeleteButton));
-                OnPropertyChanged(nameof(ShowAddButton));
-                OnPropertyChanged(nameof(ShowDoNot));
-                OnPropertyChanged(nameof(DisplayText));
-            }
-        }
-    }
-
-    private bool _isSignIn;
-    public bool IsSignIn
-    {
-        get => _isSignIn;
-        set
-        {
-            if (SetProperty(ref _isSignIn, value))
-            {
-                OnPropertyChanged(nameof(ShowSignInButton));
-                OnPropertyChanged(nameof(ShowDeleteButton));
-                OnPropertyChanged(nameof(ShowLogo));
-                OnPropertyChanged(nameof(DisplayText));
-            }
-        }
-    }
-
-    private bool _isEditing;
-    public bool IsEditing
-    {
-        get => _isEditing;
-        set
-        {
-            if (SetProperty(ref _isEditing, value))
-            {
-                OnPropertyChanged(nameof(ShowEditBox));
-                OnPropertyChanged(nameof(ShowDisplay));
-                OnPropertyChanged(nameof(ShowEditButton));
-                OnPropertyChanged(nameof(ShowDeleteButton));
-                OnPropertyChanged(nameof(ShowAddButton));
-                OnPropertyChanged(nameof(ShowDoNot));
-            }
-        }
-    }
-
-    private bool _isValidating;
-    public bool IsValidating
-    {
-        get => _isValidating;
-        set
-        {
-            if (SetProperty(ref _isValidating, value))
-            {
-                OnPropertyChanged(nameof(ShowBusy));
-                OnPropertyChanged(nameof(ShowDoNot));
-            }
-        }
-    }
-
-    private string _handle = string.Empty;
-    public string Handle
-    {
-        get => _handle;
-        set
-        {
-            if (SetProperty(ref _handle, value))
-                OnPropertyChanged(nameof(DisplayText));
-        }
-    }
-
-    private string? _fediverseSoftware;
-    public string? FediverseSoftware
-    {
-        get => _fediverseSoftware;
-        set
-        {
-            if (SetProperty(ref _fediverseSoftware, value))
-                OnPropertyChanged(nameof(LogoData));
-        }
-    }
-
-    public string ProfileUrl { get; set; } = string.Empty;
-
-    private string? _error;
-    public string? Error
-    {
-        get => _error;
-        set
-        {
-            if (SetProperty(ref _error, value))
-            {
-                OnPropertyChanged(nameof(HasError));
-                OnPropertyChanged(nameof(ShowError));
-                OnPropertyChanged(nameof(ShowDoNot));
-            }
-        }
-    }
-
-    private string _editText = string.Empty;
-    public string EditText
-    {
-        get => _editText;
-        set => SetProperty(ref _editText, value);
-    }
-
-    /// <summary>The last text submitted for validation (used to skip re-validating
-    /// identical input — e.g. a LostFocus firing as the user clicks Cancel).</summary>
-    public string? LastValidatedInput { get; set; }
-
-    public string DisplayText =>
-        IsYoutube
-            ? (IsSignIn ? "Sign in to YouTube" : Handle)
-            : IsLocked ? "Unlock with Premium"
-            : IsFilled ? Handle
-            : "No social yet";
-
-    public bool HasError => !string.IsNullOrEmpty(Error);
-    public bool ShowError => HasError;
-    public bool ShowLogo => IsYoutube ? !IsSignIn : IsFilled;
-    public bool ShowBusy => IsValidating;
-    public bool ShowEditBox => IsEditing;
-    public bool ShowDisplay => !IsEditing && !IsValidating;
-    public bool ShowSignInButton => IsYoutube && IsSignIn && !IsValidating;
-    public bool ShowAddButton => !IsYoutube && !IsLocked && !IsFilled && !IsEditing && !IsValidating;
-    public bool ShowEditButton => !IsYoutube && IsFilled && !IsEditing && !IsValidating;
-    public bool ShowDeleteButton => (IsFilled || IsYoutube) && !IsEditing && !IsValidating;
-    public bool ShowDoNot => !IsYoutube && !IsLocked && (!IsFilled || HasError || IsValidating);
-
-    public SocialSlotViewModel(int index) => Index = index;
-}
-
 /// <summary>
 /// View model for the Social Media Site Promotion dialog. Owns the working copy
 /// of the social bar config: the six fixed slots, the sign-in gate, per-row

ViewModels/index.md

@@ -58,7 +58,20 @@ Progress (Commit N/12 · tag):
 - [x] **Commit 13 · `refactor-commit-13`** — **HealthBanner** → `Controls/HealthBanner.xaml` (Row 1). Also promoted the 7 value↔visibility converters out of `MainWindow.Window.Resources` into `Themes/Controls.xaml` so extracted controls can resolve them (app-level, not window-level).
 - [x] **Commit 14 · `refactor-commit-14`** — **TopBar** → `Controls/TopBar.xaml(.cs)` (Row 0: logo, REC/ON-AIR pills + signs, avatar, Sign In/Start/End buttons). Avatar fetch moved (async-preserved) into the control; window exposes `_topBar.RefreshAvatar()` invoked on `IsConnected`/`AccountAvatarUrl` changes.
 - [x] **Commit 15 · `refactor-commit-15`** — **PreviewPane** → `Controls/PreviewPane.xaml(.cs)` (Row 1 Col 1 center preview pane). Moved the 1920×1080 canvas (OverlayCanvas/SelectionOverlay/BrandFlashLayer/SocialBarElement), text pull-out, and the live-controls row (TRAX/game/mic meters + sliders + speakers + socials button). Code-behind moved: preview drag/select/resize/hit-test (Preview_Mouse*, HitHandle, HitElement), webcam-context-menu handlers (WebcamMenu_*), social-bar glow (SocialBar_*, SocialsButton_*, SocialGlowTick), audio sliders/speakers (VolumeSlider_*, GameVolumeSlider_*, MicSpeaker_*, GameSpeaker_*, SetSliderValueFromClick, FindParent), TraxButton_*. Window keeps the source-list left panel + thumbnail strip + edit UI, and routes selection-overlay via `_previewPane.UpdateSelectionOverlay(bool)` plus `_previewPane.IsClickInsidePreview/Drawer`. `BackgroundMenu_*` stayed in the window (used by the left-panel source context menu).
-- [x] **Commit 16 · `refactor-commit-16`** — **SceneThumbnailStrip** → `Controls/SceneThumbnailStrip.xaml(.cs)` (Row 0 scene-picker strip). `Thumbnail_MouseLeftButtonDown` moved into the control (transitions via `DataContext.TransitionToScene`). Pending: left scene/chat panel, overlay host.
+- [x] **Commit 16 · `refactor-commit-16`** — **SceneThumbnailStrip** → `Controls/SceneThumbnailStrip.xaml(.cs)` (Row 0 scene-picker strip). `Thumbnail_MouseLeftButtonDown` moved into the control (transitions via `DataContext.TransitionToScene`).
+- [x] **Commit 17 · `refactor-commit-17`** — **LeftPanel** → `Controls/LeftPanel.xaml(.cs)` (Row 1 Col 0 left panel: layers/properties edit UI + live chat list). Moved ALL property-editor and chat handlers: `SourceNameBox_*`/`CommitSourceEdit`, `AddSourceButton_Click`, `OnChatMessagesChanged` (now self-subscribed on Loaded), `MirrorButton_Click`, `ShapeButton_Click`, `SourceMenu_Remove`, `BackgroundMenu_*`, `OpacitySlider_ValueChanged`, list drag-to-reorder (`_dragStartPoint`+`List_Preview*`+`EndListDrag`+`FindItemContainerAt`), and the snapshot family (`TakeSnapshot`, `WebcamBorder*`, `Countdown*`, `Web*`). Window exposes via `_leftPanel.IsClickInside(original)` (deselect guard) and `_leftPanel.OnSelectionChanged(vm)` (opacity label + snapshot). Pending: overlay host region.
+- [x] **Commit 18 · `refactor-commit-18`** — **OverlayHost** → `Controls/OverlayHost.xaml(.cs)` (settings/bug/feature/about dialogs). `BackToAbout_Click` moved with it (uses inherited `DataContext`). Window keeps the thin `WebViewHostPanel` + `ToastArea` root stubs so name lookups are untouched (WebView2 ctor init, `NotificationService.InArea("ToastArea")`) — toast/WebView2 behavior unchanged. **Phase 2 COMPLETE** — MainWindow.xaml carved down to a 123-line shell over 6 controls (TopBar, HealthBanner, BottomBar, SceneThumbnailStrip, LeftPanel, PreviewPane, OverlayHost). Pending: session wrap-up (HANDOFF.md) + push on approval.
 
+**Phase 3 — 500-line compliance (production `.cs` only).** Bring all production
+source files under 500 lines. One roll-back commit per file; same drill
+(0-warning build, `verify.sh` 246+2, explicit-file scope-check, tracker in same
+commit, tag `refactor-commit-N`, no per-commit push).
+- [x] **Commit A · `refactor-commit-A`** — **core** → `MainViewModel.cs` 758 → **495**. Moved source add/remove/image block to new **`MainViewModel.Sources.cs`** (234 lines: `AddSource`, `NextSourceName`, `AddImage`, `BuildImageCandidates`, `PickImageBytes`, `AddAsset`, `AddImageSource`, `AddReusedImage`, `RemoveElement`) and WebView2 hosting (`RegisterLoadedWebSources`, `InitWebView2`, `OnWebView2PreviewBitmapChanged`) to new **`MainViewModel.Web.cs`**. Pruned now-dead usings (`Microsoft.Win32`, `NAudio.CoreAudioApi`, `System.Windows.Media.Imaging`, `Collections.ObjectModel/Specialized`). Pending: Streaming, Background, SocialsDialogViewModel, LayoutStore.
+- [x] **Commit B · `refactor-commit-B`** — **Streaming** → `MainViewModel.Streaming.cs` 789 → **330** + new **`MainViewModel.Streaming.Operations.cs`** (459 lines). Moved the go-live/record/health operation bodies (`StartSession`, `BeginRecordOnly`, `BeginGoLive`, `StartRecordFile`, `PrepareAndStartLiveAsync`, `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue`, `StopStream`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder`, `OnFramePumpFailed`, `OnFramePumpHealthUpdated`, `ApplyHealth`, `ResetHealth`, `BuildEncoderOptions`) into the Operations partial; Streaming.cs keeps state + quality/resolution tiers + session timer + command declarations. Pruned dead usings both files. Pending: Background, SocialsDialogViewModel, LayoutStore.
+- [x] **Commit C · `refactor-commit-C`** — **Background** → `MainViewModel.Background.cs` 567 → **418** + new **`MainViewModel.Background.Model.cs`** (163 lines). Moved the static scene-model helpers (`LoadBackgroundImage`, `CreatePlaceholderSnapshot`, `EnsureBackground`, `CreateBackground`, `NormalizeBackgrounds`, `AllBackgrounds`, `ResolveAutoCaptureKey`, `MonitorKeyPrefix`) into the Model partial; Background.cs keeps capture/live state + operations (`UpdateActiveBackground`, `UpdateBackgroundImage`, `RefreshSnapshotsAsync`, `ReacquireScreenCaptures`, `OnScreenPreviewBitmapChanged`, `OnFullscreenMonitorChanged`, `RefreshBackgroundAutoCapture`, `BrowseBackground`, `ClearBackgroundCaptureAsync`, `RedesignateBackgroundAsync`, `ChangeBackgroundCaptureAsync`, `SetBackgroundCapture`, `DefaultBackgroundAsset`, `HealBackgrounds`, `StampDefaultBackgroundAsset`). Pending: SocialsDialogViewModel, LayoutStore.
+- [x] **Commit D · `refactor-commit-D`** — **SocialsDialog** → `SocialsDialogViewModel.cs` 515 → **334** + new **`SocialSlotViewModel.cs`** (183 lines). Moved the `DialogEntry` record + the row-level `SocialSlotViewModel` (six-fixed-slot row VM: service/logo/lock/edit/validate state + computed `Show*` flags) into its own file; `SocialsDialogViewModel.cs` keeps the dialog VM (sign-in gate, validation orchestration, commit). `DialogEntry` stays `public` in the same namespace so both files see it. Pending: LayoutStore.
+- [x] **Commit E · `refactor-commit-E`** — **LayoutStore** → `LayoutStore.cs` 1402 split into 6 concern-based partials: **`LayoutStore.cs`** (47: shell — `Instance`, fields, ctor + `EnsureSchema`, `GetUserVersion`, `Dispose`), **`LayoutStore.Migrations.cs`** (495: all `Migrate*` + `EnsureSchema`), **`LayoutStore.Load.cs`** (221: `Load`), **`LayoutStore.Save.cs`** (339: `Save`), **`LayoutStore.Settings.cs`** (292: mic/record-folder/reusable-stream + license/transition/broadcast/hotkey/window `GetSetting`/`UpsertSetting`), **`LayoutStore.Assets.cs`** (41: `GetAssetBytes`/`UpsertAsset`). **PHASE 3 COMPLETE — no production `.cs` over 500.**
+- [x] **Commit F · `refactor-commit-F`** — **Recording (context/concern)** → new **`MainViewModel.Recording.cs`** (121 lines). The encoder (`Services/Encoder/FfmpegEncoder.cs`) and frame pump (`Services/Encoder/FramePump.cs`) were ALREADY extracted services — the planned "extract FFmpegEncoder/StreamHealthMonitor/FramePump" was a no-op premise. The honest functional seam was the local recording-output concern: `StartRecordFile`, `FinalizeRecordingAsync`, `UniquePath`, `ChooseRecordFolder`, `ResetRecordFolder`, `DefaultRecordFolder` + fields `_recordFolder`/`RecordFolderDisplay`/`_activeRecordPath`/`_recordStartTime`/`_recordLength` moved out of the live-stream orchestration. `MainViewModel.Streaming.Operations.cs` 475 → **377**; `MainViewModel.Streaming.cs` 328 → **323**. Same partial class, MVVM glue untouched.
+- [x] **Commit G · `refactor-commit-G`** — **ChatOverlayLayer (true component)** → new **`Services/ChatOverlayLayer.cs`** (199 lines). The first REAL decomposition of the 4,105-line god-object: `MainViewModel.Chat.cs` 194 → **44** (thin delegation). The layer owns all chat behavior — `Messages` buffer, `ChatBoxRenderer`, fade timer, mock-preview timer, per-source preview renders, live-output `RenderFrame`. The VM keeps only the binding surface: `ChatMessages` (delegates to `_chatLayer.Messages`, so XAML bind + LeftPanel `CollectionChanged` hold), `CanAddYouTubeChat`/`ShowChatInactiveMessage` (computed + `OnPropertyChanged` from VM setters), and thin forwards. Scenes are handed in as args (no `Func` seam) so the layer stays scene-graph-free. Zero behavior change; 246 pass / 2 known.
 The partial `.cs` files land next to `MainViewModel.cs` in this folder as the split
 proceeds; each partial carries its own `using`s and re-declares nothing from core.