feat(core): extract execution lifecycle facade

Extracts ExecutionLifecycleService to decouple background task tracking from ShellExecutionService, enabling Ctrl+B backgrounding for any tool (including remote agents).

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

@@ -80,7 +80,7 @@ export const useShellCommandProcessor = (
   setShellInputFocused: (value: boolean) => void,
   terminalWidth?: number,
   terminalHeight?: number,
-  activeToolPtyId?: number,
+  activeBackgroundExecutionId?: number,
   isWaitingForConfirmation?: boolean,
 ) => {
   const [state, dispatch] = useReducer(shellReducer, initialState);
@@ -103,7 +103,8 @@ export const useShellCommandProcessor = (
   }
   const m = manager.current;
 
-  const activePtyId = state.activeShellPtyId || activeToolPtyId;
+  const activePtyId =
+    state.activeShellPtyId ?? activeBackgroundExecutionId ?? undefined;
 
   useEffect(() => {
     const isForegroundActive = !!activePtyId || !!isWaitingForConfirmation;
@@ -191,7 +192,8 @@ export const useShellCommandProcessor = (
   ]);
 
   const backgroundCurrentShell = useCallback(() => {
-    const pidToBackground = state.activeShellPtyId || activeToolPtyId;
+    const pidToBackground =
+      state.activeShellPtyId ?? activeBackgroundExecutionId;
     if (pidToBackground) {
       ShellExecutionService.background(pidToBackground);
       m.backgroundedPids.add(pidToBackground);
@@ -202,7 +204,7 @@ export const useShellCommandProcessor = (
         m.restoreTimeout = null;
       }
     }
-  }, [state.activeShellPtyId, activeToolPtyId, m]);
+  }, [state.activeShellPtyId, activeBackgroundExecutionId, m]);
 
   const dismissBackgroundShell = useCallback(
     (pid: number) => {

packages/cli/src/ui/hooks/useGeminiStream.test.tsx

@@ -96,6 +96,25 @@ const MockedUserPromptEvent = vi.hoisted(() =>
   vi.fn().mockImplementation(() => {}),
 );
 const mockParseAndFormatApiError = vi.hoisted(() => vi.fn());
+const mockIsBackgroundExecutionData = vi.hoisted(
+  () =>
+    (data: unknown): data is { pid?: number } => {
+      if (typeof data !== 'object' || data === null) {
+        return false;
+      }
+      const value = data as {
+        pid?: unknown;
+        command?: unknown;
+        initialOutput?: unknown;
+      };
+      return (
+        (value.pid === undefined || typeof value.pid === 'number') &&
+        (value.command === undefined || typeof value.command === 'string') &&
+        (value.initialOutput === undefined ||
+          typeof value.initialOutput === 'string')
+      );
+    },
+);
 
 const MockValidationRequiredError = vi.hoisted(
   () =>
@@ -121,6 +140,7 @@ vi.mock('@google/gemini-cli-core', async (importOriginal) => {
   const actualCoreModule = (await importOriginal()) as any;
   return {
     ...actualCoreModule,
+    isBackgroundExecutionData: mockIsBackgroundExecutionData,
     GitService: vi.fn(),
     GeminiClient: MockedGeminiClientClass,
     UserPromptEvent: MockedUserPromptEvent,
@@ -599,6 +619,35 @@ describe('useGeminiStream', () => {
     expect(mockSendMessageStream).not.toHaveBeenCalled(); // submitQuery uses this
   });
 
+  it('should expose activePtyId for non-shell executing tools that report an execution ID', () => {
+    const remoteExecutingTool: TrackedExecutingToolCall = {
+      request: {
+        callId: 'remote-call-1',
+        name: 'remote_agent_call',
+        args: {},
+        isClientInitiated: false,
+        prompt_id: 'prompt-id-remote',
+      },
+      status: CoreToolCallStatus.Executing,
+      responseSubmittedToGemini: false,
+      tool: {
+        name: 'remote_agent_call',
+        displayName: 'Remote Agent',
+        description: 'Remote agent execution',
+        build: vi.fn(),
+      } as any,
+      invocation: {
+        getDescription: () => 'Calling remote agent',
+      } as unknown as AnyToolInvocation,
+      startTime: Date.now(),
+      liveOutput: 'working...',
+      pid: 4242,
+    };
+
+    const { result } = renderTestHook([remoteExecutingTool]);
+    expect(result.current.activePtyId).toBe(4242);
+  });
+
   it('should submit tool responses when all tool calls are completed and ready', async () => {
     const toolCall1ResponseParts: Part[] = [{ text: 'tool 1 final response' }];
     const toolCall2ResponseParts: Part[] = [{ text: 'tool 2 final response' }];

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

@@ -37,6 +37,7 @@ import {
   buildUserSteeringHintPrompt,
   GeminiCliOperation,
   getPlanModeExitMessage,
+  isBackgroundExecutionData,
 } from '@google/gemini-cli-core';
 import type {
   Config,
@@ -94,10 +95,10 @@ type ToolResponseWithParts = ToolCallResponseInfo & {
   llmContent?: PartListUnion;
 };
 
-interface ShellToolData {
-  pid?: number;
-  command?: string;
-  initialOutput?: string;
+interface BackgroundedToolInfo {
+  pid: number;
+  command: string;
+  initialOutput: string;
 }
 
 enum StreamProcessingStatus {
@@ -111,15 +112,32 @@ const SUPPRESSED_TOOL_ERRORS_NOTE =
 const LOW_VERBOSITY_FAILURE_NOTE =
   'This request failed. Press F12 for diagnostics, or run /settings and change "Error Verbosity" to full for full details.';
 
-function isShellToolData(data: unknown): data is ShellToolData {
-  if (typeof data !== 'object' || data === null) {
-    return false;
+function getBackgroundedToolInfo(
+  toolCall: TrackedCompletedToolCall | TrackedCancelledToolCall,
+): BackgroundedToolInfo | undefined {
+  const response = toolCall.response as ToolResponseWithParts;
+  const rawData: unknown = response?.data;
+  if (!isBackgroundExecutionData(rawData)) {
+    return undefined;
   }
-  const d = data as Partial<ShellToolData>;
+
+  if (rawData.pid === undefined) {
+    return undefined;
+  }
+
+  return {
+    pid: rawData.pid,
+    command: rawData.command ?? toolCall.request.name,
+    initialOutput: rawData.initialOutput ?? '',
+  };
+}
+
+function isBackgroundableExecutingToolCall(
+  toolCall: TrackedToolCall,
+): toolCall is TrackedExecutingToolCall {
   return (
-    (d.pid === undefined || typeof d.pid === 'number') &&
-    (d.command === undefined || typeof d.command === 'string') &&
-    (d.initialOutput === undefined || typeof d.initialOutput === 'string')
+    toolCall.status === CoreToolCallStatus.Executing &&
+    typeof toolCall.pid === 'number'
   );
 }
 
@@ -311,13 +329,11 @@ export const useGeminiStream = (
     getPreferredEditor,
   );
 
-  const activeToolPtyId = useMemo(() => {
-    const executingShellTool = toolCalls.find(
-      (tc) =>
-        tc.status === 'executing' && tc.request.name === 'run_shell_command',
+  const activeBackgroundExecutionId = useMemo(() => {
+    const executingBackgroundableTool = toolCalls.find(
+      isBackgroundableExecutingToolCall,
     );
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-    return (executingShellTool as TrackedExecutingToolCall | undefined)?.pid;
+    return executingBackgroundableTool?.pid;
   }, [toolCalls]);
 
   const onExec = useCallback(async (done: Promise<void>) => {
@@ -347,7 +363,7 @@ export const useGeminiStream = (
     setShellInputFocused,
     terminalWidth,
     terminalHeight,
-    activeToolPtyId,
+    activeBackgroundExecutionId,
   );
 
   const streamingState = useMemo(
@@ -525,7 +541,8 @@ export const useGeminiStream = (
     onComplete: (result: { userSelection: 'disable' | 'keep' }) => void;
   } | null>(null);
 
-  const activePtyId = activeShellPtyId || activeToolPtyId;
+  const activePtyId =
+    activeShellPtyId ?? activeBackgroundExecutionId ?? undefined;
 
   const prevActiveShellPtyIdRef = useRef<number | null>(null);
   useEffect(() => {
@@ -1651,26 +1668,16 @@ export const useGeminiStream = (
           !processedMemoryToolsRef.current.has(t.request.callId),
       );
 
-      // Handle backgrounded shell tools
-      completedAndReadyToSubmitTools.forEach((t) => {
-        const isShell = t.request.name === 'run_shell_command';
-        // Access result from the tracked tool call response
-        const response = t.response as ToolResponseWithParts;
-        const rawData = response?.data;
-        const data = isShellToolData(rawData) ? rawData : undefined;
-
-        // Use data.pid for shell commands moved to the background.
-        const pid = data?.pid;
-
-        if (isShell && pid) {
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-          const command = (data?.['command'] as string) ?? 'shell';
-          // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
-          const initialOutput = (data?.['initialOutput'] as string) ?? '';
-
-          registerBackgroundShell(pid, command, initialOutput);
+      for (const toolCall of completedAndReadyToSubmitTools) {
+        const backgroundedTool = getBackgroundedToolInfo(toolCall);
+        if (backgroundedTool) {
+          registerBackgroundShell(
+            backgroundedTool.pid,
+            backgroundedTool.command,
+            backgroundedTool.initialOutput,
+          );
         }
-      });
+      }
 
       if (newSuccessfulMemorySaves.length > 0) {
         // Perform the refresh only if there are new ones.