refactor: split Overlays out of MainViewModel — Commit 11/12

MainViewModel.Overlays.cs (194 lines) takes the settings/bug/feature/about
panels + creator-hub links: panel state (IsSettingsOpen/IsBugOpen/IsFeatureOpen/
IsAboutOpen via SetPanel, IsLicensesOpen, IsAnyOverlayOpen, OverlayTitle),
ShowOverlay/ShowLicenses, bug/feature report fields + SubmitBug/SubmitFeature/
ComposeEmail/OpenUrl, the About-hub consts (ChannelUrl/MastodonUrl/CoffeeUrl/
PremiumUrl/IsPremiumAvailable), SupportEmail/AppVersionLabel, LicensesText, and
the overlay command declarations (OpenSettingsCommand..OpenLicensesCommand).
Core drops 940 -> 758 lines. Ctor command assignments and all other wiring stay
in core; SetPanel/ShowOverlay keep their cross-partial calls.

This completes Phase 1: MainViewModel.cs has been split into 10 functional
partials (1,890 -> 758 lines in core).

Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures.
Docs: index.md Overlays row added, About-hub row re-pointed, tracker marked
Phase 1 complete in the same commit.

ViewModels/MainViewModel.Chat.cs

@@ -0,0 +1,194 @@
+using System.Collections.ObjectModel;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Threading;
+using ytLive.Helpers;
+using ytLive.Models;
+using ytLive.Services;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+
+    private readonly ChatBoxRenderer _chatBoxRenderer;
+
+    // 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 Add → YouTube Chat menu item: enabled only while no chat layer exists
+    /// anywhere — one chat overlay per layout.</summary>
+    public bool CanAddYouTubeChat
+        => StagedScene != null
+           && !Scenes.Any(s => s.Elements.OfType<Source>().Any(e => e.Type == SourceType.ChatBox));
+
+    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);
+
+            // 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 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;
+            }
+        }
+    }
+
+    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);
+    }
+
+    private void StopMockChatPreview()
+    {
+        _mockChatCts?.Cancel();
+        _mockChatCts?.Dispose();
+        _mockChatCts = 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>
+    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);
+            }
+    }
+}

ViewModels/MainViewModel.Overlays.cs

@@ -0,0 +1,193 @@
+using System.Diagnostics;
+using System.IO;
+using System.Windows.Input;
+using ytLive.Helpers;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+
+    private bool _isSettingsOpen;
+    private bool _isBugOpen;
+    private bool _isFeatureOpen;
+    private bool _isAboutOpen;
+    private bool _isLicensesOpen;
+    private string _overlayTitle = string.Empty;
+    private string _bugReportText = string.Empty;
+    private string _bugReportEmail = string.Empty;
+    private string _featureRequestText = string.Empty;
+    private string _featureRequestEmail = string.Empty;
+
+    private const string SupportEmail = "gramps@llamachile.shop";
+    // The creator-hub link targets (About overlay) — public so the hub's
+    // integration test can assert they point at real destinations.
+    public const string ChannelUrl = "https://youtube.com/@llamachileshop";
+    public const string MastodonUrl = "https://mastodon.llamachile.tube/@gramps";
+    public const string PremiumUrl = "https://buy.polar.sh/polar_cl_ueMy8AyAClO0o0yo19IroZwKTbD587gzUsjEW3bFapw";
+    public const string CoffeeUrl = "https://buymeacoffee.com/llamachiley";
+    public static string AppVersionLabel => $"Version {typeof(MainViewModel).Assembly.GetName().Version?.ToString(3)}";
+
+    /// <summary>The About hub's Unlock Premium button lights up only once the
+    /// billing URL is set (Polar — polar.sh, pending TASK 10 implementation).</summary>
+    public bool IsPremiumAvailable => PremiumUrl.Length > 0;
+
+    /// <summary>Full in-app licensing/legal text, loaded on demand from the
+    /// shipped THIRD-PARTY-NOTICES.txt (never opens the OS viewer).</summary>
+    public string LicensesText { get; private set; } = string.Empty;
+
+    // Overlay panels
+    public bool IsSettingsOpen
+    {
+        get => _isSettingsOpen;
+        private set => SetPanel(ref _isSettingsOpen, value);
+    }
+
+    public bool IsBugOpen
+    {
+        get => _isBugOpen;
+        private set => SetPanel(ref _isBugOpen, value);
+    }
+
+    public bool IsFeatureOpen
+    {
+        get => _isFeatureOpen;
+        private set => SetPanel(ref _isFeatureOpen, value);
+    }
+
+    public bool IsAboutOpen
+    {
+        get => _isAboutOpen;
+        private set => SetPanel(ref _isAboutOpen, value);
+    }
+
+    /// <summary>About hub sub-view: the full licensing/legal texts panel
+    /// (in-app scrolling — no Notepad, no browser tab).</summary>
+    public bool IsLicensesOpen
+    {
+        get => _isLicensesOpen;
+        set
+        {
+            if (SetProperty(ref _isLicensesOpen, value))
+                OnPropertyChanged(nameof(IsHubVisible));
+        }
+    }
+
+    public bool IsAnyOverlayOpen => IsSettingsOpen || IsBugOpen || IsFeatureOpen || IsAboutOpen;
+
+    public string OverlayTitle
+    {
+        get => _overlayTitle;
+        private set => SetProperty(ref _overlayTitle, value);
+    }
+
+    public string BugReportText
+    {
+        get => _bugReportText;
+        set => SetProperty(ref _bugReportText, value);
+    }
+
+    public string BugReportEmail
+    {
+        get => _bugReportEmail;
+        set => SetProperty(ref _bugReportEmail, value);
+    }
+
+    public string FeatureRequestText
+    {
+        get => _featureRequestText;
+        set => SetProperty(ref _featureRequestText, value);
+    }
+
+    public string FeatureRequestEmail
+    {
+        get => _featureRequestEmail;
+        set => SetProperty(ref _featureRequestEmail, value);
+    }
+
+    public ICommand OpenSettingsCommand { get; }
+    public ICommand OpenBugCommand { get; }
+    public ICommand OpenFeatureCommand { get; }
+    public ICommand OpenAboutCommand { get; }
+    public ICommand CloseOverlayCommand { get; }
+    public ICommand SubmitBugCommand { get; }
+    public ICommand SubmitFeatureCommand { get; }
+    public ICommand OpenChannelCommand { get; }
+    public ICommand OpenMastodonCommand { get; }
+    public ICommand OpenCoffeeCommand { get; }
+    public ICommand OpenPremiumCommand { get; }
+    public ICommand OpenLicensesCommand { get; }
+
+    private void SetPanel(ref bool field, bool value, [System.Runtime.CompilerServices.CallerMemberName] string? propertyName = null)
+    {
+        if (SetProperty(ref field, value, propertyName))
+            OnPropertyChanged(nameof(IsAnyOverlayOpen));
+    }
+
+    private void ShowOverlay(string? panel = null, string title = "")
+    {
+        IsSettingsOpen = panel == nameof(IsSettingsOpen);
+        IsBugOpen = panel == nameof(IsBugOpen);
+        IsFeatureOpen = panel == nameof(IsFeatureOpen);
+        IsAboutOpen = panel == nameof(IsAboutOpen);
+        OverlayTitle = title;
+        if (panel != nameof(IsAboutOpen))
+            IsLicensesOpen = false;
+    }
+
+    /// <summary>Shows the in-app licensing panel, loading the full texts from
+    /// the shipped THIRD-PARTY-NOTICES.txt on first open (never the OS viewer).
+    /// Falls back to a "not found" note if the file is missing so the panel
+    /// never hangs on nothing.</summary>
+    private void ShowLicenses()
+    {
+        if (string.IsNullOrEmpty(LicensesText))
+        {
+            try
+            {
+                var path = Path.Combine(AppContext.BaseDirectory, "THIRD-PARTY-NOTICES.txt");
+                LicensesText = File.Exists(path)
+                    ? File.ReadAllText(path)
+                    : "THIRD-PARTY-NOTICES.txt not found next to the executable.";
+            }
+            catch (Exception ex)
+            {
+                LicensesText = $"Could not read THIRD-PARTY-NOTICES.txt: {ex.Message}";
+            }
+        }
+        IsLicensesOpen = true;
+    }
+
+    private void SubmitBug()
+    {
+        var body = string.Join(Environment.NewLine,
+            BugReportText.Trim(),
+            string.Empty,
+            $"LlamaCasty {AppVersionLabel}",
+            string.IsNullOrWhiteSpace(BugReportEmail) ? string.Empty : $"Reply-to: {BugReportEmail.Trim()}");
+        ComposeEmail("[LlamaCasty Bug Report]", body);
+        ShowOverlay();
+    }
+
+    private void SubmitFeature()
+    {
+        var body = string.Join(Environment.NewLine,
+            FeatureRequestText.Trim(),
+            string.Empty,
+            $"LlamaCasty {AppVersionLabel}",
+            string.IsNullOrWhiteSpace(FeatureRequestEmail) ? string.Empty : $"Reply-to: {FeatureRequestEmail.Trim()}");
+        ComposeEmail("[LlamaCasty Feature Request]", body);
+        ShowOverlay();
+    }
+
+    private static void ComposeEmail(string subject, string body)
+    {
+        var uri = $"mailto:{SupportEmail}?subject={Uri.EscapeDataString(subject)}&body={Uri.EscapeDataString(body)}";
+        OpenUrl(uri);
+    }
+
+    private static void OpenUrl(string url)
+    {
+        Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
+    }
+}

ViewModels/MainViewModel.Streaming.cs

@@ -0,0 +1,789 @@
+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;
+using ytLive.Services.Encoder;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel : ViewModelBase
+{
+
+    private readonly DispatcherTimer _liveTimer;
+    private readonly DispatcherTimer _healthPollTimer;
+
+    private StreamStatus _streamStatus = StreamStatus.Offline;
+    private StreamHealth _currentHealth = new();
+    private string _streamTitle = string.Empty;
+    private string _streamDescription = string.Empty;
+    private string _streamVisibility = "Private";
+    private string? _currentBroadcastId;
+    private string? _reusableStreamUrl;
+    private ReusableStream? _reusableStream;
+    private string? _healthIssueBanner;
+    private string _healthIssueBackground = "Transparent";
+    private string _windowTitle = "LlamaCasty";
+    private string _topBarBackground = "#16213e";
+    private string _previewGlowBrush = "Transparent";
+    private Thickness _previewGlowThickness = new(0);
+    private string _liveElapsedText = "00:00:00";
+    private double _recDotPulse = 1.0;
+    private TimeSpan _liveElapsed;
+
+    // ─── Recording (TASK 18): independent REC / ON-AIR pills. The pills are
+    // ─── intent; IsRecording / IsLive are reality. ON-AIR needs a sign-in.
+    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;
+
+    public StreamStatus StreamStatus
+    {
+        get => _streamStatus;
+        set
+        {
+            if (SetProperty(ref _streamStatus, value))
+            {
+                OnPropertyChanged(nameof(IsOffline));
+                OnPropertyChanged(nameof(IsLive));
+                OnPropertyChanged(nameof(IsEditMode));
+                OnPropertyChanged(nameof(RecDotBrush));
+                OnPropertyChanged(nameof(RecTextBrush));
+                OnPropertyChanged(nameof(RecDotOpacity));
+                OnPropertyChanged(nameof(OnAirBrush));
+                OnPropertyChanged(nameof(IsLivePrivate));
+                OnPropertyChanged(nameof(ShowPrimaryStartButton));
+                OnPropertyChanged(nameof(ShowLogInButton));
+                OnPropertyChanged(nameof(ShowEndStreamButton));
+                OnPropertyChanged(nameof(EndButtonText));
+                OnPropertyChanged(nameof(AccountStatusLightToolTip));
+                OnPropertyChanged(nameof(ShowChatInactiveMessage));
+                OnPropertyChanged(nameof(ShowPreviewPlaceholder));
+                UpdateLiveVisuals();
+            }
+        }
+    }
+
+    public bool IsOffline => StreamStatus == StreamStatus.Offline;
+    public bool IsLive => StreamStatus == StreamStatus.Streaming;
+    public bool IsLivePrivate => IsLive && string.Equals(StreamVisibility, "Private", StringComparison.OrdinalIgnoreCase);
+    public string RecDotBrush => !IsRecording ? "#555555" : "#e94560";
+    public string RecTextBrush => (IsLive || IsRecording) ? "#ffffff" : "#888888";
+    public double RecDotOpacity => IsRecording ? _recDotPulse : 0.55;
+    public string OnAirBrush => !IsLive ? "#555555" : IsLivePrivate ? "#22c55e" : "#e94560";
+
+    // ─── REC / ON-AIR pills (TASK 18) ───
+    public bool RecordPillOn
+    {
+        get => _recordPillOn;
+        set
+        {
+            if (!SetProperty(ref _recordPillOn, value)) return;
+            OnPropertyChanged(nameof(ShowPrimaryStartButton));
+            OnPropertyChanged(nameof(CanStartSession));
+        }
+    }
+
+    public bool OnAirPillOn
+    {
+        get => _onAirPillOn;
+        set
+        {
+            if (value && !CanToggleOnAir) return; // needs a sign-in
+            if (!SetProperty(ref _onAirPillOn, value)) return;
+            OnPropertyChanged(nameof(ShowPrimaryStartButton));
+            OnPropertyChanged(nameof(CanStartSession));
+        }
+    }
+
+    /// <summary>The ON-AIR pill (and thus live streaming) needs a YouTube sign-in.</summary>
+    public bool CanToggleOnAir => IsConnected;
+
+    /// <summary>Whether the session is actively recording — the REC status light
+    /// turns green only when this is true (the pill is intent, this is reality).</summary>
+    public bool IsRecording
+    {
+        get => _isRecording;
+        private set
+        {
+            if (!SetProperty(ref _isRecording, value)) return;
+            OnPropertyChanged(nameof(RecDotBrush));
+            OnPropertyChanged(nameof(RecTextBrush));
+            OnPropertyChanged(nameof(RecDotOpacity));
+            OnPropertyChanged(nameof(IsEditMode));
+            OnPropertyChanged(nameof(ShowEndStreamButton));
+            OnPropertyChanged(nameof(ShowPrimaryStartButton));
+            OnPropertyChanged(nameof(EndButtonText));
+            UpdateSessionTimer();
+        }
+    }
+
+    /// <summary>The primary button shows when there's something to start, but never
+    /// while a session is running — once recording/live the ONLY control is the End
+    /// button.</summary>
+    public bool ShowPrimaryStartButton =>
+        IsOffline && !IsRecording && !IsLive
+        && (IsConnected || (RecordPillOn && !OnAirPillOn));
+
+    /// <summary>Either output selected makes the button actionable.</summary>
+    public bool CanStartSession => RecordPillOn || OnAirPillOn;
+
+    /// <summary>The End button shows while recording OR live.</summary>
+    public bool ShowEndStreamButton => IsLive || IsRecording;
+
+    /// <summary>The one button whose label changes: while recording it reads
+    /// "Stop Recording", while live "End Stream".</summary>
+    public string EndButtonText => IsRecording && !IsLive ? "Stop Recording" : "End Stream";
+
+    public bool ShowLogInButton => !IsConnected && IsOffline && !IsRecording;
+
+    public StreamHealth CurrentHealth
+    {
+        get => _currentHealth;
+        set => SetProperty(ref _currentHealth, value);
+    }
+
+    /// <summary>Report-by-exception YouTube health (TASK 5 item 3): non-null only
+    /// while a warning/error configuration issue exists — the banner's text.
+    /// good/ok/noData keep it null so nothing renders.</summary>
+    public string? HealthIssueBanner
+    {
+        get => _healthIssueBanner;
+        private set => SetProperty(ref _healthIssueBanner, value);
+    }
+
+    /// <summary>Banner background: app red (#8f1f1f) for an error issue, amber
+    /// (#b8860b) for a warning. Transparent when no banner is shown.</summary>
+    public string HealthIssueBackground
+    {
+        get => _healthIssueBackground;
+        private set => SetProperty(ref _healthIssueBackground, value);
+    }
+
+    public string StreamTitle
+    {
+        get => _streamTitle;
+        set => SetProperty(ref _streamTitle, value);
+    }
+
+    public string StreamDescription
+    {
+        get => _streamDescription;
+        set => SetProperty(ref _streamDescription, value);
+    }
+
+    public string StreamVisibility
+    {
+        get => _streamVisibility;
+        set
+        {
+            if (SetProperty(ref _streamVisibility, value))
+            {
+                OnPropertyChanged(nameof(RecDotBrush));
+                OnPropertyChanged(nameof(RecTextBrush));
+                OnPropertyChanged(nameof(OnAirBrush));
+                OnPropertyChanged(nameof(IsLivePrivate));
+            }
+        }
+    }
+
+    public string WindowTitle
+    {
+        get => _windowTitle;
+        set => SetProperty(ref _windowTitle, value);
+    }
+
+    public string TopBarBackground
+    {
+        get => _topBarBackground;
+        set => SetProperty(ref _topBarBackground, value);
+    }
+
+    public string PreviewGlowBrush
+    {
+        get => _previewGlowBrush;
+        set => SetProperty(ref _previewGlowBrush, value);
+    }
+
+    public Thickness PreviewGlowThickness
+    {
+        get => _previewGlowThickness;
+        set => SetProperty(ref _previewGlowThickness, value);
+    }
+
+    public string LiveElapsedText
+    {
+        get => _liveElapsedText;
+        set => SetProperty(ref _liveElapsedText, value);
+    }
+
+    // ─── Broadcast metadata pull-out (the "Text" tab on the Live screen) ───
+
+    /// <summary>The broadcast id of the current/last session; null until Go Live
+    /// succeeds. Gates the pull-out's Update button (nothing remote to patch).</summary>
+    public string? CurrentBroadcastId => _currentBroadcastId;
+
+    public Services.LiveBroadcastFormViewModel BroadcastForm { get; }
+
+    // ─── Resolution quality dropdown (bottom bar) ───
+    // Tiers offered to the creator before going live. First = default. The
+    // dropdown is disabled while live because YouTube stream resolution is
+    // immutable after stream creation (see TASKS.md compliance notes).
+
+    // The composition master frame. Every tier is an output rect + target
+    // resolution over this frame (see ai.md "Resolution tiers"): 16:9 tiers
+    // use the full frame; the vertical tier uses a centered 9:16 window and
+    // the preview dims the cropped strips (semi-crop).
+    private const double MasterFrameWidth = 1920;
+    private const double MasterFrameHeight = 1080;
+
+    public QualityOption[] QualityOptions { get; } =
+    {
+        new("1080p60", 60, 8.0, 1920, 1080),
+        new("1080p30", 30, 8.0, 1920, 1080),
+        new("720p60", 60, 6.0, 1280, 720),
+        new("720p30", 30, 6.0, 1280, 720),
+        new("Vertical 1080p60", 60, 8.0, 1080, 1920),
+    };
+
+    public string ResolutionHelp { get; } =
+        "Pick the highest resolution your upload bandwidth can comfortably sustain. " +
+        "Find your upload speed on your ISP plan or with a speed test (e.g. fast.com), " +
+        "then choose a tier your upload comfortably exceeds. 1080p60 is the default.";
+
+    private QualityOption _selectedQuality;
+    public QualityOption SelectedQuality
+    {
+        get => _selectedQuality;
+        set
+        {
+            if (SetProperty(ref _selectedQuality, value))
+                ApplyStreamQuality(value);
+        }
+    }
+
+    // Output frame of the selected tier over the 1920x1080 master. The strips
+    // outside it are dimmed in the preview so the cropped area stays visible.
+    public double OutputRectX { get; private set; }
+    public double OutputRectY { get; private set; }
+    public double OutputRectWidth { get; private set; }
+    public double OutputRectHeight { get; private set; }
+    public bool IsOutputCropped { get; private set; }
+    public string ResolutionBadgeText { get; private set; } = string.Empty;
+    public ObservableCollection<Rect> DimRects { get; } = new();
+
+    private void ApplyStreamQuality(QualityOption quality)
+    {
+        var health = CurrentHealth;
+        health.CurrentBitrate = quality.Bitrate;
+        health.FPS = quality.Fps;
+        OnPropertyChanged(nameof(CurrentHealth));
+
+        var scale = Math.Min(MasterFrameWidth / quality.Width, MasterFrameHeight / quality.Height);
+        var rectW = quality.Width * scale;
+        var rectH = quality.Height * scale;
+        var rectX = (MasterFrameWidth - rectW) / 2;
+        var rectY = (MasterFrameHeight - rectH) / 2;
+
+        OutputRectX = rectX;
+        OutputRectY = rectY;
+        OutputRectWidth = rectW;
+        OutputRectHeight = rectH;
+
+        DimRects.Clear();
+        if (rectX > 0) DimRects.Add(new Rect(0, 0, rectX, MasterFrameHeight));
+        if (rectX + rectW < MasterFrameWidth)
+            DimRects.Add(new Rect(rectX + rectW, 0, MasterFrameWidth - rectX - rectW, MasterFrameHeight));
+        if (rectY > 0) DimRects.Add(new Rect(0, 0, MasterFrameWidth, rectY));
+        if (rectY + rectH < MasterFrameHeight)
+            DimRects.Add(new Rect(0, rectY + rectH, MasterFrameWidth, MasterFrameHeight - rectY - rectH));
+
+        IsOutputCropped = DimRects.Count > 0;
+        ResolutionBadgeText = $"{quality.Label} · {quality.Width}×{quality.Height}";
+
+        OnPropertyChanged(nameof(OutputRectX));
+        OnPropertyChanged(nameof(OutputRectY));
+        OnPropertyChanged(nameof(OutputRectWidth));
+        OnPropertyChanged(nameof(OutputRectHeight));
+        OnPropertyChanged(nameof(IsOutputCropped));
+        OnPropertyChanged(nameof(ResolutionBadgeText));
+    }
+
+    public ICommand StartStreamCommand { get; }
+    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/index.md

@@ -8,7 +8,7 @@ areas' docs in their own rows keeps this index small to read.
 
 | File | Purpose |
 |------|---------|
-| `MainViewModel.cs` | Core. `public partial class MainViewModel : ViewModelBase`. **Broadcast/stream state:** go-live (`BeginGoLive` accepts the GoLive dialog → `StreamVisibility` always "Private" → `CreateBroadcastAsync` storing `_currentBroadcastId` for the bind/transition; failure → `StreamStatus.Error` + `_framePump.StartAsync()`), End (`StopStream` — signs out, clears session/token/`_currentBroadcastId`, crash-safe), `StreamStatus`/`StreamVisibility` setters, `IsOffline`/`IsLive`/`IsLivePrivate`. **Health stats:** `CurrentHealth`/`ResetHealth`/`OnFramePumpHealthUpdated` marshal `FramePump.HealthUpdated` (encoder bitrate/FPS/dropped/duration) off the stderr thread onto the UI thread. **Start/End UI:** REC/ON-AIR pills (`RecordPillOn`/`OnAirPillOn`, `CanStartSession`, `ShowPrimaryStartButton`/`ShowEndStreamButton`/`EndButtonText`), REC sign (`RecDotBrush`/`RecTextBrush`/`RecDotOpacity`, pulsing live via `_recDotPulse`), `ShowLogInButton`, `ChooseRecordFolder`/`ResetRecordFolder`/`_recordFolder`. **Resolution dropdown:** `QualityOptions`/`SelectedQuality`/`ResolutionHelp`/`ApplyStreamQuality` computes the output rect over the 1920×1080 master (`OutputRectX/Y/W/H`, `DimRects`, `IsOutputCropped`, `ResolutionBadgeText`). **Source commands + element rows:** scenes are pure selection rows; sources carry edit/visibility/trash (`EditElementCommand` sets `element.IsEditing`, `ToggleElementVisibilityCommand` flips `IsVisible`, `RemoveSourceCommand`; Backdrop trash slot reserved via `HiddenBoolToVisibilityConverter` — TASK 13); shared `NextSourceName` (Image, Image2, Image3… no-space increment from actual names — used by `AddSource` + `AddReusedImage`), `AddImageCommand`. **Overlays/lifecycle:** fields + ctor wiring (all command assignments, mixer/camera/chat/hotkey/subscription hookups), `Shutdown`/`SaveLayoutNow`/`ScheduleSave`/`LoadLayout`, `SetPanel`/`ShowOverlay`/`ShowLicenses`, `CreateBrush` + shared `BarOnBrush`/`BarOffBrush` (referenced by Audio/Trax partials), `OpenUrl`/`ComposeEmail`/`SubmitBug`/`SubmitFeature`, window-geometry pass-through, `SelectedElement`/`OnSelectedElementPropertyChanged`, `ShowPreviewPlaceholder`/`ShowChatInactiveMessage`, `BrandFlash*`, WebView2 hosting (`InitWebView2`/`RegisterLoadedWebSources`/`OnWebView2PreviewBitmapChanged`). |
+| `MainViewModel.cs` | Core. `public partial class MainViewModel : ViewModelBase`. **Source commands + element rows:** scenes are pure selection rows; sources carry edit/visibility/trash (`EditElementCommand` sets `element.IsEditing`, `ToggleElementVisibilityCommand` flips `IsVisible`, `RemoveSourceCommand`; Backdrop trash slot reserved via `HiddenBoolToVisibilityConverter` — TASK 13); shared `NextSourceName` (Image, Image2, Image3… no-space increment from actual names — used by `AddSource` + `AddReusedImage`), `AddImageCommand`. **Lifecycle/ctor wiring:** fields + ctor wiring (all command assignments, mixer/camera/chat/hotkey/subscription hookups), `Shutdown`/`SaveLayoutNow`/`ScheduleSave`/`LoadLayout`, `CreateBrush` + shared `BarOnBrush`/`BarOffBrush` (referenced by Audio/Trax/Socials partials), window-geometry pass-through, `SelectedElement`/`OnSelectedElementPropertyChanged`, `ShowPreviewPlaceholder`, `BrandFlash*`, WebView2 hosting (`InitWebView2`/`RegisterLoadedWebSources`/`OnWebView2PreviewBitmapChanged`), frame-pump wiring (construction + `_rtmpUrlProvider` seam + `Dispose`, plus `ResolveOutputFrame` → `RenderChatBox` for chat layers) — the pump's stream-state consumers live in the Streaming partial. |
 | `MainViewModel.Account.cs` | Session + connected account: `LoadSavedSessionAsync` (DPAPI restore at startup), `SignInAsync`/`ChangeAccountAsync`/`SignOutYouTubeAsync`, `IsConnected`/`AccountAvatarUrl`/`AccountDisplayName`/`AccountStatusLightToolTip` via `SyncConnectedAccount` (cleared on End). |
 | `MainViewModel.License.cs` | Polar license (freemium): `LicenseKey`/`LicenseMessage`/`IsLicenseValidating`/`IsLicenseEntryOpen`/`IsHubVisible`/`IsPremium`, `OfflineGracePeriod`, `ValidateLicenseAtStartupAsync`/`ActivateLicenseAsync`. |
 | `MainViewModel.Scenes.cs` | Five-scene catalog: `Scenes` + `StagedScene`/`LiveScene`/`IsEditMode`, `AddScene` (canonical names only), `MissingScenes`/`ShowAddScene`/`AddSceneCommand`; scene wiring `OnScenesChanged`/`WireScene`/`UnwireScene`; transitions `SelectedTransitionType`/`TransitionDurationMs`/`TransitionToScene`/`ApplyTransitionToLive`; global hotkeys `HandleHotkey`/`OpenHotkeyConfig`/`RefreshHotkeyLabels`; scene-gating hints (`CanChangeBackground`). |
@@ -17,8 +17,11 @@ areas' docs in their own rows keeps this index small to read.
 | `MainViewModel.Audio.cs` | **Mic bar:** read-only realtime meter `AudioLevel`/`MeterFillWidth`/`MeterBrush` (fill = `Math.Min(1, AudioLevelMeter.ToDisplay((float)AudioLevel) * MicVolume)`, green→yellow→red at 60%/80% zones), `MicVolume` (0.8 default; drives `MicMuted` ⇔ volume 0; unmute flash `BeginVolumeFlash`/`EndVolumeFlash`/`CancelVolumeFlash`), `MicSourceName` (left-justified inside the bar, persists via `LayoutStore.Settings`), `ToggleMicMute`/`PickMicrophone` (`MicPickerDialog`; picked device swaps the live source via `_audioMixer.RestartMic()`, loopback keeps running), status dot `MicStatus`/`MicStatusBrush`/`MicStatusToolTip` (`Models.MicStatus`: green Connected / yellow Problem / red no-device), capture starts once at startup (`StartMicCaptureAsync`) — NOT go-live. **Game audio bar:** overlaid bottom-center, always visible (show/hide gating removed 2026-08-15); `GameAudioLevel` (loopback via `OnLoopbackLevelChanged`), `GameAudioVolume`/`GameMuted`/`GameMuteText`/`ToggleGameMute`/`PushSystemVolume`, mirror volume flash `SetGameVolumeAdjusting`/`BeginGameVolumeFlash`/`EndGameVolumeFlash`/`CancelGameVolumeFlash`. Mixer handlers `OnMicLevelChanged`/`OnLoopbackLevelChanged`/`OnMicConnected`/`OnMicFailed`. |
 | `MainViewModel.Trax.cs` | Background music (TASK 9, rides the loopback into the stream): `_musicPlayer` (`MusicPlayer`), `IsMusicPlaying`/`TraxError`/`TraxDotBrush`/`TraxToolTip`, interaction `TraxLeftClick`/`TraxRightClick`/`PickTraxTrack`, playback `LoadTrax`/`PlayTrax`/`PauseTrax`/`OnTraxPlaybackEnded`/`RefreshTraxUi`, `UpdateTraxLocalGain` (mirrors the game bar's mute onto `MusicPlayer.LocalGain` so the track ducks/restores with desktop audio). |
 | `MainViewModel.Socials.cs` | Social bar (global resource, overlaid on every scene): `_socials`/`_socialBarFrame`/`_socialValidator` (`ISocialValidator`/`HttpSocialValidator`), `HasSocials`/`SocialBarVisible`/`SocialBarDotBrush`/`SocialBarGlowBrush`/`Socials`/`SocialBarTop`, `OpenSocialDialogCommand`/`OpenSocialDialog` (spawns `SocialsDialogViewModel` + window; saved copy replaces `_socials`), `NotifySocialsChanged`/`RenderSocialBarFrame` (`SocialBarRenderer` → immutable `_socialBarFrame` the frame pump reads), fediverse heal `HealFediverseSoftwareAsync` (static, test-facing) + `HealFediverseSoftwareInBackground`, bar edge toggle `SetSocialBarPosition`/`ToggleSocialBarPosition`. `BarOnBrush`/`BarOffBrush`/`CreateBrush` stay in core (shared tokens). |
+| `MainViewModel.Streaming.cs` | Go-live/record + health + quality tiers + session UI. **Stream state:** `StreamStatus`/`StreamVisibility` setters + `_streamStatus` field, `IsOffline`/`IsLive`/`IsLivePrivate`. **Go-live flow:** `StartSession` (routes by pill state) → `BeginRecordOnly` (signed-out local recording) or `BeginGoLive` (GoLive dialog → captures title/description/visibility + `BroadcastForm.CaptureGoLive` → `PrepareAndStartLiveAsync`: reusable stream → `CreateBroadcast` (stores `_currentBroadcastId`) → empty-metadata warn → chat poll start (liveChatId) → `_framePump.StartAsync()` + health poll; failures → `StreamStatus.Error`, never a crash); `StartRecordFile` (auto-named `ty-…-0000.mp4`) + `FinalizeRecordingAsync` (rename modal, `UniquePath`); `StopStream` (posts Offline, stops chat/audio pipe/pump, clears `_currentBroadcastId`; session/token deliberately NOT cleared — sign-out stays explicit). **Health:** `CurrentHealth`/`ResetHealth`/`ApplyHealth`/`OnFramePumpHealthUpdated` (marshal `FramePump.HealthUpdated` off the stderr thread), `PollHealthAsync`/`OnHealthPollTick`/`ApplyHealthIssue` (report-by-exception banner `HealthIssueBanner`/`HealthIssueBackground` via `StreamHealthReporter`). **Session timer:** `_liveTimer` (ctor-wired) `UpdateSessionTimer`/`OnLiveTimerTick`/`LiveElapsedText`/`_recDotPulse`. **Start/End UI:** REC/ON-AIR pills (`RecordPillOn`/`OnAirPillOn`/`CanToggleOnAir`), `ShowPrimaryStartButton`/`CanStartSession`/`ShowEndStreamButton`/`EndButtonText`/`ShowLogInButton`, REC sign `RecDotBrush`/`RecTextBrush`/`RecDotOpacity`/`OnAirBrush`, live window tokens `WindowTitle`/`TopBarBackground`/`PreviewGlow*` via `UpdateLiveVisuals`; `ChooseRecordFolder`/`ResetRecordFolder`/`_recordFolder`/`RecordFolderDisplay`/`DefaultRecordFolder`. **Resolution dropdown:** `QualityOptions`/`SelectedQuality`/`ResolutionHelp`/`ApplyStreamQuality` + `OutputRect*`/`DimRects`/`IsOutputCropped`/`ResolutionBadgeText` over the 1920×1080 master. **Pipeline bits:** `_framePump`/`_liveTimer`/`_healthPollTimer` fields, `BuildEncoderOptions`. Commands `StartStreamCommand`/`EndStreamCommand`/`ChooseRecordFolderCommand`/`ResetRecordFolderCommand`. Broadcast pull-out: `CurrentBroadcastId`/`BroadcastForm`. |
+| `MainViewModel.Overlays.cs` | Settings/bug/feature/about panels + creator-hub links: panel state `IsSettingsOpen`/`IsBugOpen`/`IsFeatureOpen`/`IsAboutOpen` (via `SetPanel` → `IsAnyOverlayOpen`), `IsLicensesOpen` (flips `IsHubVisible`), `OverlayTitle`, `ShowOverlay` (one-panel exclusivity) + `ShowLicenses` (loads shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` on first open, never the OS viewer); bug/feature report `BugReportText`/`BugReportEmail`/`FeatureRequestText`/`FeatureRequestEmail` + `SubmitBug`/`SubmitFeature`/`ComposeEmail`/`OpenUrl`; About hub consts `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` (public, integration-test live) + `PremiumUrl` (tabled billing seam — TASK 12 → greyed "Unlock Premium" lights up when filled) + `IsPremiumAvailable` + `SupportEmail` + `AppVersionLabel`; commands `OpenSettingsCommand`/`OpenBugCommand`/`OpenFeatureCommand`/`OpenAboutCommand`/`CloseOverlayCommand`/`SubmitBugCommand`/`SubmitFeatureCommand`/`OpenChannelCommand`/`OpenMastodonCommand`/`OpenCoffeeCommand`/`OpenPremiumCommand`/`OpenLicensesCommand`. Ctor command assignments stay in core. |
+| `MainViewModel.Chat.cs` | Chat overlay + preview pipeline: `ChatMessages` (500-message cap; clear-on-fade), `OnChatMessageReceived` (marshal `_youtubeChat.MessageReceived` onto the dispatcher, switch previews mock→real), fade `_chatFadeTimer`/`ResetChatFadeTimer` (shortest `ChatFadeSeconds` across chat layers); live render `RenderChatBox` (called from `ResolveOutputFrame`, stays in core) + preview render `UpdateChatBoxPreview` (bitmap onto `chatBox.VideoImageSource`); mock preview `MockChatMessages`/`StartMockChatPreview`/`StopMockChatPreview`/`RunMockChatPreviewAsync`/`_mockChatCts`; `UpdateActiveChatBoxPreviews` (wires Chat* property-change subscriptions + first render); `CanAddYouTubeChat` (one-per-layout gate), `ShowChatInactiveMessage` (`!IsLive`). `_chatBoxRenderer` field. Ctor wiring (`MessageReceived` hookup, `new ChatBoxRenderer()`, `LoadLayout` preview start, `_youtubeChat.Dispose`) stays in core. |
 | `GoLiveViewModel.cs` | Start Stream dialog: **account row** (saved channel shown with Change Account, or Sign in to YouTube; Start gated on `IsSignedIn`/`IsBusy`) + title/description + **locked Visibility (always "Private" — ship step 7, no dropdown)**, start/cancel requests |
-| **About hub (TASK 11, in `MainViewModel`)** | the About overlay is the in-app creator hub: `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` (public consts, live) + `PremiumUrl` (tabled billing seam — TASK 12 → the greyed "Unlock Premium" button lights up when filled); `OpenLicensesCommand` → `ShowLicenses()` loads the shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` and sets `IsLicensesOpen` (in-app scrolling panel, never the OS viewer); `BackToAbout_Click` in `MainWindow.xaml.cs` flips it off. |
+| **About hub (TASK 11, in `MainViewModel.Overlays.cs`)** | the About overlay is the in-app creator hub: `ChannelUrl`/`MastodonUrl`/`CoffeeUrl` (public consts, live) + `PremiumUrl` (tabled billing seam — TASK 12 → the greyed "Unlock Premium" button lights up when filled); `OpenLicensesCommand` → `ShowLicenses()` loads the shipped `THIRD-PARTY-NOTICES.txt` into `LicensesText` and sets `IsLicensesOpen` (in-app scrolling panel, never the OS viewer); `BackToAbout_Click` in `MainWindow.xaml.cs` flips it off. |
 | `ReuseImageViewModel.cs` | Add Image dialog: candidate list (`ReuseImageCandidate`), reuse/new/cancel |
 | `CameraPickerViewModel.cs` | Add Webcam dialog: async camera list (loading / has / none states), `UseRequested(CameraDeviceInfo)`/`CancelRequested` |
 | `MicPickerViewModel.cs` | Select Microphone dialog (voice source): async mic list (loading / has / none states), `UseRequested(MicrophoneDeviceInfo)`/`CancelRequested` |
@@ -45,9 +48,10 @@ Progress (Commit N/12 · tag):
 - [x] **Commit 6/12 · `refactor-commit-6`** — **Audio** → `MainViewModel.Audio.cs`
 - [x] **Commit 7/12 · `refactor-commit-7`** — **Trax** → `MainViewModel.Trax.cs`
 - [x] **Commit 8/12 · `refactor-commit-8`** — **Socials** → `MainViewModel.Socials.cs`
-- [ ] **Commit 9/12** — **Streaming** (go-live/record + health + quality tiers + media source pipeline)
-- [ ] **Commit 10/12** — **Chat** (YouTube chat + mock preview + chatbox render)
-- [ ] **Commit 11/12** — **Overlays** (settings/bug/feature/about panels + license entry)
+- [x] **Commit 9/12 · `refactor-commit-9`** — **Streaming** → `MainViewModel.Streaming.cs`
+- [x] **Commit 10/12 · `refactor-commit-10`** — **Chat** → `MainViewModel.Chat.cs`
+- [x] **Commit 11/12 · `refactor-commit-11`** — **Overlays** → `MainViewModel.Overlays.cs`
+- [x] **Phase 1 complete:** core `MainViewModel.cs` split into 10 functional partials (1,890 → 758 lines). Phase 2 (splitting `MainWindow.xaml` into UserControls) not yet started.
 
 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.