Phase 3.1: Local notification for WS chat requests, router fix, cleanup

- Show local notification (sound + vibrate) when chat_request arrives
  via WebSocket while mitra app is backgrounded
- Add NotificationService.showLocalNotification() for programmatic use
- Fix router redirect: don't redirect auth routes to splash during loading
- Handle binary/string WebSocket frames in ChatRequestNotifier
- Remove debug logging from backend and Flutter
- Control center: mitra ping config UI
- Both apps: dynamic ping, FCM deep-linking, unread badges

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

mitra_app/lib/core/chat/chat_request_notifier.dart

@@ -7,6 +7,7 @@ import 'package:web_socket_channel/web_socket_channel.dart';
 import '../api/api_client.dart';
 import '../api/api_client_provider.dart';
 import '../constants.dart';
+import '../notifications/notification_service.dart';
 
 part 'chat_request_notifier.g.dart';
 
@@ -77,9 +78,12 @@ class ChatRequest extends _$ChatRequest {
 
       _wsSubscription = _channel!.stream.listen(
         (raw) {
-          final data = jsonDecode(raw as String) as Map<String, dynamic>;
-          if (data['type'] == WsMessage.authOk) return;
-          _onRequestReceived(data);
+          try {
+            final text = raw is String ? raw : String.fromCharCodes(raw as List<int>);
+            final data = jsonDecode(text) as Map<String, dynamic>;
+            if (data['type'] == WsMessage.authOk) return;
+            _onRequestReceived(data);
+          } catch (_) {}
         },
         onError: (_) => _onConnectionError(),
         onDone: () => _onConnectionError(),
@@ -105,7 +109,14 @@ class ChatRequest extends _$ChatRequest {
     final type = data['type'] as String?;
 
     if (type == WsMessage.chatRequest) {
-      state = ChatRequestIncomingData(data['session_id'] as String);
+      final sessionId = data['session_id'] as String;
+      state = ChatRequestIncomingData(sessionId);
+      // Show local notification so mitra is alerted even when app is backgrounded
+      NotificationService.showLocalNotification(
+        title: 'Permintaan Chat Baru',
+        body: 'Ada pelanggan yang ingin curhat! Ketuk untuk menerima.',
+        data: {'type': 'chat_request', 'session_id': sessionId, 'action': 'open_accept'},
+      );
     } else if (type == WsMessage.chatRequestClosed) {
       if (state is ChatRequestIncomingData) {
         state = const ChatRequestListeningData();