fix terminal input ids across page re-entry

apps/mobile_app/lib/features/terminal/terminal_session_coordinator.dart

@@ -31,6 +31,8 @@ class TerminalViewport {
 }
 
 class TerminalSessionCoordinator extends ChangeNotifier {
+  static int _inputDispatchInstanceCounter = 0;
+
   TerminalSessionCoordinator({
     required this.controller,
     required this.apiClient,
@@ -46,7 +48,8 @@ class TerminalSessionCoordinator extends ChangeNotifier {
     ResizeScheduler? resizeScheduler,
   }) : baseUri = baseUri ?? _defaultBaseUri,
        _reconnectScheduler = reconnectScheduler ?? _defaultReconnectScheduler,
-       _resizeScheduler = resizeScheduler ?? _defaultResizeScheduler;
+       _resizeScheduler = resizeScheduler ?? _defaultResizeScheduler,
+       _inputDispatchScope = _buildInputDispatchScope(session.sessionId);
 
   static final Uri _defaultBaseUri = Uri(
     scheme: 'https',
@@ -71,6 +74,7 @@ class TerminalSessionCoordinator extends ChangeNotifier {
   final TerminalDiagnosticLog? diagnosticLog;
   final ReconnectScheduler _reconnectScheduler;
   final ResizeScheduler _resizeScheduler;
+  final String _inputDispatchScope;
 
   TerminalSocketSession? _socketSession;
   CancelReconnect? _cancelReconnect;
@@ -797,7 +801,12 @@ class TerminalSessionCoordinator extends ChangeNotifier {
 
   String _buildPendingInputId() {
     _nextInputId += 1;
-    return '${session.sessionId}-input-$_nextInputId';
+    return '$_inputDispatchScope-input-$_nextInputId';
+  }
+
+  static String _buildInputDispatchScope(String sessionId) {
+    _inputDispatchInstanceCounter += 1;
+    return '$sessionId-${_inputDispatchInstanceCounter}';
   }
 }
 

apps/mobile_app/test/features/terminal/terminal_session_coordinator_test.dart

@@ -123,7 +123,11 @@ void main() {
 
       expect(sessionFactory.createdSessions, hasLength(2));
       expect(sessionFactory.createdSessions.last.sentInputs, ['dir\r']);
-      expect(sessionFactory.createdSessions.last.sentInputIds, ['abc-input-1']);
+      expect(sessionFactory.createdSessions.last.sentInputIds, hasLength(1));
+      expect(
+        sessionFactory.createdSessions.last.sentInputIds.single,
+        endsWith('-input-1'),
+      );
     },
   );
 
@@ -154,16 +158,17 @@ void main() {
       final firstSession = sessionFactory.createdSessions.single;
 
       coordinator.sendInput('dir\r');
-      expect(firstSession.sentInputIds, ['abc-input-1']);
+      final firstInputId = firstSession.sentInputIds.single;
+      expect(firstInputId, endsWith('-input-1'));
 
       firstSession.disconnect();
       await reconnectScheduler.runPending();
 
       final secondSession = sessionFactory.createdSessions.last;
       expect(secondSession.sentInputs, ['dir\r']);
-      expect(secondSession.sentInputIds, ['abc-input-1']);
+      expect(secondSession.sentInputIds, [firstInputId]);
 
-      secondSession.ackInput('abc-input-1');
+      secondSession.ackInput(firstInputId);
       secondSession.disconnect();
       await reconnectScheduler.runPending();
 
@@ -172,6 +177,53 @@ void main() {
     },
   );
 
+  test('re-entering the same session generates fresh input ids', () async {
+    final firstController = TerminalInteractionController();
+    final firstApiClient = _FakeAgentApiClient();
+    final firstSessionFactory = _FakeTerminalSessionFactory();
+    final session = Session(
+      sessionId: 'abc',
+      name: 'codex-main',
+      status: 'idle',
+    );
+    final firstCoordinator = TerminalSessionCoordinator(
+      controller: firstController,
+      apiClient: firstApiClient,
+      session: session,
+      sessionFactory: firstSessionFactory.create,
+      onFrame: (_) {},
+      onRestore: (_) {},
+      viewportProvider: () => const TerminalViewport(columns: 80, rows: 24),
+    );
+
+    await firstCoordinator.start();
+    firstCoordinator.sendInput('dir\r');
+    final firstInputId = firstSessionFactory.createdSessions.single.sentInputIds.single;
+    await firstCoordinator.close();
+
+    final secondController = TerminalInteractionController();
+    final secondApiClient = _FakeAgentApiClient();
+    final secondSessionFactory = _FakeTerminalSessionFactory();
+    final secondCoordinator = TerminalSessionCoordinator(
+      controller: secondController,
+      apiClient: secondApiClient,
+      session: session,
+      sessionFactory: secondSessionFactory.create,
+      onFrame: (_) {},
+      onRestore: (_) {},
+      viewportProvider: () => const TerminalViewport(columns: 80, rows: 24),
+    );
+
+    await secondCoordinator.start();
+    secondCoordinator.sendInput('dir\r');
+    final secondInputId = secondSessionFactory.createdSessions.single.sentInputIds.single;
+
+    expect(secondInputId, isNot(firstInputId));
+    expect(firstInputId, endsWith('-input-1'));
+    expect(secondInputId, endsWith('-input-1'));
+    await secondCoordinator.close();
+  });
+
   test('restore payloads are treated as authoritative over provisional text', () {
     final decision = decideTerminalRestore(
       currentText: 'PS> git status\r\nmodified: file.txt\r\nPS> ',