fix(cli): resolve TTY hang on headless environments by unconditionally resuming process.stdin before React Ink launch (#23673)

packages/cli/src/gemini.test.tsx

@@ -528,6 +528,62 @@ describe('gemini.tsx main function kitty protocol', () => {
     );
   });
 
+  it('should call process.stdin.resume when isInteractive is true to protect against implicit Node pause', async () => {
+    const resumeSpy = vi.spyOn(process.stdin, 'resume');
+    vi.mocked(loadCliConfig).mockResolvedValue(
+      createMockConfig({
+        isInteractive: () => true,
+        getQuestion: () => '',
+        getSandbox: () => undefined,
+      }),
+    );
+    vi.mocked(loadSettings).mockReturnValue(
+      createMockSettings({
+        merged: {
+          advanced: {},
+          security: { auth: {} },
+          ui: {},
+        },
+      }),
+    );
+    vi.mocked(parseArguments).mockResolvedValue({
+      model: undefined,
+      sandbox: undefined,
+      debug: undefined,
+      prompt: undefined,
+      promptInteractive: undefined,
+      query: undefined,
+      yolo: undefined,
+      approvalMode: undefined,
+      policy: undefined,
+      adminPolicy: undefined,
+      allowedMcpServerNames: undefined,
+      allowedTools: undefined,
+      experimentalAcp: undefined,
+      extensions: undefined,
+      listExtensions: undefined,
+      includeDirectories: undefined,
+      screenReader: undefined,
+      useWriteTodos: undefined,
+      resume: undefined,
+      listSessions: undefined,
+      deleteSession: undefined,
+      outputFormat: undefined,
+      fakeResponses: undefined,
+      recordResponses: undefined,
+      rawOutput: undefined,
+      acceptRawOutputRisk: undefined,
+      isCommand: undefined,
+    });
+
+    await act(async () => {
+      await main();
+    });
+
+    expect(resumeSpy).toHaveBeenCalledTimes(1);
+    resumeSpy.mockRestore();
+  });
+
   it.each([
     { flag: 'listExtensions' },
     { flag: 'listSessions' },

packages/cli/src/gemini.tsx

@@ -613,8 +613,17 @@ export async function main() {
     }
 
     cliStartupHandle?.end();
+
     // Render UI, passing necessary config values. Check that there is no command line question.
     if (config.isInteractive()) {
+      // Earlier initialization phases (like TerminalCapabilityManager resolving
+      // or authWithWeb) may have added and removed 'data' listeners on process.stdin.
+      // When the listener count drops to 0, Node.js implicitly pauses the stream buffer.
+      // React Ink's useInput hooks will silently fail to receive keystrokes if the stream remains paused.
+      if (process.stdin.isTTY) {
+        process.stdin.resume();
+      }
+
       await startInteractiveUI(
         config,
         settings,