Phase 3.1 WS2: FCM fallback Flutter + CC, unread badges, dynamic ping

- Control center: add mitra ping config UI (require ping toggle + interval)
- Mitra app StatusNotifier: honor require_ping and ping_interval_seconds
  from API; skip heartbeat when ping not required
- Both apps: update notification services for FCM deep-linking
  - mitra_app: handle chat_request (open_accept), session_closing
  - client_app: handle session_closing, paired
- Unread badge providers:
  - mitra_app: UnreadSessions provider (polls active-with-unread, badge
    on active sessions button)
  - client_app: UnreadCount provider (polls active-with-unread, badge
    on _ActiveSessionCard)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mitra_app/lib/core/chat/unread_notifier.dart

@@ -0,0 +1,54 @@
+import 'dart:async';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import '../api/api_client_provider.dart';
+
+part 'unread_notifier.g.dart';
+
+@Riverpod(keepAlive: true)
+class UnreadSessions extends _$UnreadSessions {
+  Timer? _pollTimer;
+
+  @override
+  Map<String, int> build() {
+    _startPolling();
+    ref.onDispose(_stopPolling);
+    return {};
+  }
+
+  void _startPolling() {
+    _stopPolling();
+    _fetchUnreadCounts();
+    _pollTimer = Timer.periodic(const Duration(seconds: 15), (_) {
+      _fetchUnreadCounts();
+    });
+  }
+
+  void _stopPolling() {
+    _pollTimer?.cancel();
+    _pollTimer = null;
+  }
+
+  Future<void> _fetchUnreadCounts() async {
+    try {
+      final apiClient = ref.read(apiClientProvider);
+      final response = await apiClient.get('/api/mitra/chat-requests/sessions/active-with-unread');
+      final sessions = response['data'] as List<dynamic>;
+      final counts = <String, int>{};
+      for (final s in sessions) {
+        final id = s['id'] as String;
+        final count = s['unread_count'] as int? ?? 0;
+        if (count > 0) counts[id] = count;
+      }
+      state = counts;
+    } catch (_) {}
+  }
+
+  int get totalUnread => state.values.fold(0, (a, b) => a + b);
+
+  void markSessionRead(String sessionId) {
+    state = {...state}..remove(sessionId);
+  }
+
+  void refresh() => _fetchUnreadCounts();
+}

mitra_app/lib/core/chat/unread_notifier.g.dart

@@ -0,0 +1,26 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'unread_notifier.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$unreadSessionsHash() => r'd2ff837f1e781e6aa624b3d3ca2befb0d1d258e8';
+
+/// See also [UnreadSessions].
+@ProviderFor(UnreadSessions)
+final unreadSessionsProvider =
+    NotifierProvider<UnreadSessions, Map<String, int>>.internal(
+  UnreadSessions.new,
+  name: r'unreadSessionsProvider',
+  debugGetCreateSourceHash: const bool.fromEnvironment('dart.vm.product')
+      ? null
+      : _$unreadSessionsHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef _$UnreadSessions = Notifier<Map<String, int>>;
+// ignore_for_file: type=lint
+// ignore_for_file: subtype_of_sealed_class, invalid_use_of_internal_member, invalid_use_of_visible_for_testing_member, deprecated_member_use_from_same_package

mitra_app/lib/core/notifications/notification_service.dart

@@ -84,12 +84,21 @@ class NotificationService {
   }
 
   static void _navigateFromMessage(Map<String, dynamic> data) {
+    if (_router == null) return;
     final sessionId = data['session_id'] as String?;
-    if (sessionId == null || _router == null) return;
-
     final type = data['type'] as String?;
-    if (type == 'chat_message' || type == 'chat_request') {
-      _router!.push('/chat/session/$sessionId');
+    final action = data['action'] as String?;
+
+    if (type == 'chat_request' && action == 'open_accept') {
+      // Navigate to home where incoming request sheet will show
+      _router!.go('/home');
+    } else if (type == 'session_closing' || type == 'session_expired') {
+      // Navigate to the chat session closure screen
+      if (sessionId != null) {
+        _router!.push('/chat/session/$sessionId', extra: {'customerName': 'Customer'});
+      }
+    } else if (type == 'chat_message' && sessionId != null) {
+      _router!.push('/chat/session/$sessionId', extra: {'customerName': 'Customer'});
     }
   }
 }

mitra_app/lib/core/status/status_notifier.dart

@@ -30,6 +30,8 @@ class StatusErrorData extends OnlineStatusData {
 @Riverpod(keepAlive: true)
 class OnlineStatus extends _$OnlineStatus {
   Timer? _heartbeatTimer;
+  bool _requirePing = true;
+  int _pingIntervalSeconds = 15;
 
   @override
   OnlineStatusData build() => const StatusInitialData();
@@ -38,6 +40,8 @@ class OnlineStatus extends _$OnlineStatus {
     try {
       final response = await ref.read(apiClientProvider).get('/api/mitra/status');
       final data = response['data'] as Map<String, dynamic>;
+      _requirePing = data['require_ping'] as bool? ?? true;
+      _pingIntervalSeconds = data['ping_interval_seconds'] as int? ?? 15;
       state = StatusLoadedData(isOnline: data['is_online'] as bool);
     } catch (e) {
       state = const StatusLoadedData(isOnline: false);
@@ -48,7 +52,7 @@ class OnlineStatus extends _$OnlineStatus {
     state = const StatusLoadingData();
     try {
       await ref.read(apiClientProvider).post('/api/mitra/status/online');
-      _startHeartbeat();
+      if (_requirePing) _startHeartbeat();
       state = const StatusLoadedData(isOnline: true);
     } catch (e) {
       state = const StatusErrorData('Gagal mengubah status. Coba lagi.');
@@ -67,11 +71,11 @@ class OnlineStatus extends _$OnlineStatus {
   }
 
   void onAppPaused() {
-    _stopHeartbeat();
+    if (_requirePing) _stopHeartbeat();
   }
 
   void onAppResumed() {
-    if (state is StatusLoadedData && (state as StatusLoadedData).isOnline) {
+    if (_requirePing && state is StatusLoadedData && (state as StatusLoadedData).isOnline) {
       _startHeartbeat();
     }
     load();
@@ -79,7 +83,7 @@ class OnlineStatus extends _$OnlineStatus {
 
   void _startHeartbeat() {
     _stopHeartbeat();
-    _heartbeatTimer = Timer.periodic(const Duration(seconds: 15), (_) {
+    _heartbeatTimer = Timer.periodic(Duration(seconds: _pingIntervalSeconds), (_) {
       _heartbeatTick();
     });
   }

mitra_app/lib/features/home/home_screen.dart

@@ -4,6 +4,7 @@ import 'package:go_router/go_router.dart';
 import '../../core/auth/auth_notifier.dart';
 import '../../core/status/status_notifier.dart';
 import '../../core/chat/chat_request_notifier.dart';
+import '../../core/chat/unread_notifier.dart';
 import '../chat/widgets/incoming_request_sheet.dart';
 
 class HomeScreen extends ConsumerStatefulWidget {
@@ -159,16 +160,23 @@ class _StatusToggle extends ConsumerWidget {
   }
 }
 
-class _ActiveSessionsButton extends StatelessWidget {
+class _ActiveSessionsButton extends ConsumerWidget {
   const _ActiveSessionsButton();
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
+    final unreadCounts = ref.watch(unreadSessionsProvider);
+    final totalUnread = unreadCounts.values.fold(0, (a, b) => a + b);
+
     return Column(
       children: [
         Card(
           child: ListTile(
-            leading: const Icon(Icons.chat_bubble_outline),
+            leading: Badge(
+              isLabelVisible: totalUnread > 0,
+              label: Text('$totalUnread'),
+              child: const Icon(Icons.chat_bubble_outline),
+            ),
             title: const Text('Sesi Aktif'),
             trailing: const Icon(Icons.chevron_right),
             onTap: () => context.push('/sessions'),