feat(ui): interactive chat composer in the session terminal + work console

SessionTerminalView gains an opt-in composer (IsComposerVisible / ComposerText /
SubmitCommand / ComposerPlaceholder styled props); Mission Control binds it to the
monitor VM. Task detail's WorkConsole output tab gets a matching shell-prompt
composer bound through Monitor.*, shown only while an interactive session is live.
log-user lines render in the accent color. Adds session.composer.* (en/de).

src/ClaudeDo.Ui/Design/IslandStyles.axaml

@@ -528,6 +528,10 @@
   <Style Selector="Border.terminal TextBlock[Tag=log-msg]">
     <Setter Property="Foreground" Value="{StaticResource TextDimBrush}" />
   </Style>
+  <!-- log-user: user's own messages in interactive sessions — accent color to stand out -->
+  <Style Selector="Border.terminal TextBlock[Tag=log-user]">
+    <Setter Property="Foreground" Value="{DynamicResource AccentBrush}" />
+  </Style>
 
   <!-- ============================================================ -->
   <!-- TERMINAL HEADER                                              -->