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/Views/Islands/SessionTerminalView.axaml

@@ -50,6 +50,29 @@
         </Border>
       </Grid>
 
+      <!-- ── Composer bar ── -->
+      <Border DockPanel.Dock="Bottom"
+              IsVisible="{Binding #Root.IsComposerVisible}"
+              Background="{DynamicResource Surface2Brush}"
+              BorderBrush="{DynamicResource LineBrush}"
+              BorderThickness="0,1,0,0"
+              Padding="6,5">
+        <Grid ColumnDefinitions="*,Auto">
+          <TextBox Grid.Column="0"
+                   Text="{Binding #Root.ComposerText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
+                   PlaceholderText="{Binding #Root.ComposerPlaceholder}"
+                   AcceptsReturn="False">
+            <TextBox.KeyBindings>
+              <KeyBinding Gesture="Enter" Command="{Binding #Root.SubmitCommand}"/>
+            </TextBox.KeyBindings>
+          </TextBox>
+          <Button Grid.Column="1"
+                  Margin="6,0,0,0"
+                  Content="{loc:Tr session.composer.send}"
+                  Command="{Binding #Root.SubmitCommand}"/>
+        </Grid>
+      </Border>
+
       <!-- ── Log output ── -->
       <ScrollViewer Name="LogScroll"
                     VerticalScrollBarVisibility="Visible"