fix(ui): no space inside the wordmark — adjacent Runs again

The comment I added between the two <Run> elements introduced whitespace, and whitespace between
inline Runs collapses to a rendered space: the wordmark read "LlamaCas ty". The comment moved
above the TextBlock, the Runs are contiguous, and UiShellTests asserts them adjacent so a future
edit cannot re-introduce the gap.

Controls/TopBar.xaml

@@ -22,10 +22,11 @@
                         <ContentPresenter/>
                     </ControlTemplate>
                 </Button.Template>
+                <!-- Wordmark: "LlamaCas" + "ty" in YouTube red (creator ruling 2026-10-30 — never
+                     re-colour it). The Run elements MUST stay adjacent: whitespace between inline
+                     Runs renders as a space and splits the name into "LlamaCas ty". -->
                 <TextBlock FontSize="22" FontWeight="Bold" VerticalAlignment="Center">
-                    <Run Text="LlamaCas" Foreground="{StaticResource Brush.OnSurface}"/><!-- Creator ruling (2026-10-30, asked repeatedly): the wordmark's "ty" is YouTube red.
+                    <Run Text="LlamaCas" Foreground="{StaticResource Brush.OnSurface}"/><Run Text="ty" Foreground="{StaticResource Brush.Youtube}"/><Run
-                             It is brand, not state — do not re-tokenise it to an accent. -->
-                        <Run Text="ty" Foreground="{StaticResource Brush.Youtube}"/><Run
                         x:Name="BuildIdStamp" Text="{x:Static helpers:BuildStamp.Label}" FontSize="9"
                         BaselineAlignment="Superscript" Foreground="{StaticResource Brush.OnSurfaceVariant}"
                         ToolTipService.ToolTip="{x:Static helpers:BuildStamp.Label}"/><Run Text=" " FontSize="4"/>

ytLive.Tests/UiShellTests.cs

@@ -63,7 +63,9 @@ public class UiShellTests
     public void The_wordmark_ty_stays_youtube_red_and_ctrl_opens_the_context_menu()
     {
         var topBar = SourceAssert.Text("Controls", "TopBar.xaml");
-        Assert.Contains("<Run Text=\"ty\" Foreground=\"{StaticResource Brush.Youtube}\"/>", topBar);
+        // Adjacent, with nothing between: whitespace inside a TextBlock between inline Runs
+        // collapses to a space and prints "LlamaCas ty" (this exact bug shipped once).
+        Assert.Contains("<Run Text=\"LlamaCas\" Foreground=\"{StaticResource Brush.OnSurface}\"/><Run Text=\"ty\" Foreground=\"{StaticResource Brush.Youtube}\"/>", topBar);
 
         // Plain right-click is the zoom box; the context menu moved to Ctrl+right-click so a
         // creator can change capture sources mid-stream.