style(topbar): build-77 feedback — big account avatar (26→40), gear nudged right, 32px action cluster

Creator feedback on the live #77 build:
1. Avatar = 'much bigger, showing the youtube login account' — the streaming
   account's face went 26→40 px (CornerRadius 20, 20pt fallback initial) so the
   identity is readable across the room.
2. Gear moved a couple more places right (margin 6→18) — cleaner separation from
   the wordmark after the TASK 42 relocation.
3. Uniform height: the REC|ON-AIR segments host, Start/Go Live, and Test now all
   sit at Height=32 so the switch + its actions read as one family ('so the user
   can intuit their purpose'). Running-world reality line untouched.

XAML-only; compile-verified (only the running-app exe-lock copy errors remain).
verify.sh full gate deferred until the app is closed (see HANDOFF).

Controls/TopBar.xaml

@@ -29,9 +29,10 @@
                         ToolTipService.ToolTip="{x:Static helpers:BuildStamp.Label}"/><Run Text=" " FontSize="4"/>
                 </TextBlock>
             </Button>
-            <!-- Settings gear (user directive): a couple characters beyond the brand.
+            <!-- Settings gear (user directive): a couple characters beyond the brand,
+                 nudged right a couple more places 2026-09-22 (build 77 feedback).
                  Moved up from the bottom bar — one menu: App Settings / Bug / Feature / About. -->
-            <Button Style="{StaticResource IconButton}" Margin="6,0,0,2" VerticalAlignment="Center"
+            <Button Style="{StaticResource IconButton}" Margin="18,0,0,2" VerticalAlignment="Center"
                     ToolTip="Menu" Click="GearButton_Click">
                 <Button.ContextMenu>
                     <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
@@ -53,10 +54,12 @@
              reality line + End so nothing mid-session can be re-armed. -->
         <StackPanel Grid.Column="1" Orientation="Horizontal"
                     HorizontalAlignment="Center" VerticalAlignment="Center">
-            <!-- IDLE: the mode switch + the action(s) of the armed world -->
+            <!-- IDLE: the mode switch + the action(s) of the armed world. The three
+                 controls share one height (build 77 feedback) so they read as one
+                 family — segments host, Start/Go Live, and Test all sit at 32. -->
             <StackPanel Orientation="Horizontal"
                         Visibility="{Binding ShowIdleWorld, Converter={StaticResource BoolToVis}}">
-                <Border Background="#0f1622" CornerRadius="4" Padding="2" VerticalAlignment="Center">
+                <Border Background="#0f1622" CornerRadius="4" Padding="2" Height="32" VerticalAlignment="Center">
                     <StackPanel Orientation="Horizontal">
                         <ToggleButton Style="{StaticResource SegmentToggle}"
                                       IsChecked="{Binding RecordPillOn}">
@@ -71,12 +74,12 @@
                 <!-- Go face names the world: "Start Recording" vs "Go Live".
                      (Signed-out ON-AIR Start routes to the sign-in — StartSession.) -->
                 <Button Content="{Binding PrimaryStartButtonLabel}" Style="{StaticResource YtButton}"
-                        Margin="10,0,0,0" Command="{Binding StartStreamCommand}"
+                        Height="32" Margin="10,0,0,0" Command="{Binding StartStreamCommand}"
                         Visibility="{Binding ShowPrimaryStartButton, Converter={StaticResource BoolToVis}}"/>
                 <!-- Test is a child of Stream — a dry-run of the livestream, so it
                      exists only inside the Stream world (stream armed + signed in). -->
                 <Button Content="Test" Style="{StaticResource YtButtonSecondary}" Padding="12,4" FontSize="11"
-                        Margin="8,0,0,0" VerticalAlignment="Center"
+                        Height="32" Margin="8,0,0,0" VerticalAlignment="Center"
                         Command="{Binding StartTestCommand}"
                         ToolTip="Run a private test broadcast to check your chat overlay."
                         Visibility="{Binding ShowTestButton, Converter={StaticResource BoolToVis}}"/>
@@ -97,8 +100,9 @@
         </StackPanel>
 
         <!-- Account zone: lives only in the Stream world. Signed out → Sign In;
-             signed in → the avatar (which account is about to stream). Record world
-             has no YouTube identity at all. -->
+             signed in → a big avatar of the streaming account (build 77 feedback:
+             "make the user icon much bigger"). Record world has no YouTube
+             identity at all. -->
         <StackPanel Grid.Column="2" Orientation="Horizontal" VerticalAlignment="Center">
             <Button Content="Sign In" Style="{StaticResource YtButtonSecondary}"
                     Margin="0,0,8,0" Command="{Binding SignInCommand}"
@@ -114,11 +118,11 @@
                         <MenuItem Header="Logout" Command="{Binding LogoutCommand}"/>
                     </ContextMenu>
                 </Button.ContextMenu>
-                <Border Width="26" Height="26" CornerRadius="13" Background="#16213e"
+                <Border Width="40" Height="40" CornerRadius="20" Background="#16213e"
                         ClipToBounds="True" BorderBrush="#3a4a66" BorderThickness="1">
                     <Grid>
                         <Image x:Name="AvatarImage" Stretch="UniformToFill"/>
-                        <TextBlock x:Name="AvatarInitial" Foreground="#e0e0e0" FontSize="13"
+                        <TextBlock x:Name="AvatarInitial" Foreground="#e0e0e0" FontSize="20"
                                    FontWeight="Bold" HorizontalAlignment="Center" VerticalAlignment="Center"
                                    Visibility="Collapsed"/>
                     </Grid>