feat: Implement background shell commands (#14849)

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -82,6 +82,7 @@ interface SlashCommandProcessorActions {
   toggleDebugProfiler: () => void;
   dispatchExtensionStateUpdate: (action: ExtensionUpdateAction) => void;
   addConfirmUpdateExtensionRequest: (request: ConfirmationRequest) => void;
+  toggleBackgroundShell: () => void;
   setText: (text: string) => void;
 }
 
@@ -237,6 +238,7 @@ export const useSlashCommandProcessor = (
         addConfirmUpdateExtensionRequest:
           actions.addConfirmUpdateExtensionRequest,
         removeComponent: () => setCustomDialog(null),
+        toggleBackgroundShell: actions.toggleBackgroundShell,
       },
       session: {
         stats: session.stats,