feat(ui): highlight user chat messages + opt-in interrupt (stop) button

LogKindForegroundConverter drives the log message foreground via a local
binding (beats the dim local value), so user messages render in the accent
color instead of vanishing into the transcript. Adds a small stop (Icon.Stop)
button next to Send in both composers (SessionTerminalView + WorkConsole) wired
to InterruptInteractiveCommand → InterruptInteractiveSessionAsync. Adds
session.composer.interrupt (en/de).

src/ClaudeDo.App/App.axaml

@@ -21,6 +21,7 @@
             <converters:DotBrushConverter          x:Key="DotBrush"/>
             <converters:BoolToItalicConverter      x:Key="BoolToItalic"/>
             <converters:BoolToDraftOpacityConverter x:Key="BoolToDraftOpacity"/>
+            <converters:LogKindForegroundConverter  x:Key="LogKindForeground"/>
 
         </ResourceDictionary>
     </Application.Resources>