Phase 3 testing fixes: Fastify 5, SSE→WebSocket+FCM, enums, security, session lifecycle

- Upgrade Fastify 4→5 with all plugins (@fastify/websocket 11, cors 11, sensible 6)
- Migrate all SSE endpoints to WebSocket + FCM push (mitra chat requests, customer pairing status)
- Add flutter_local_notifications for foreground push notifications with sound
- Add splash screen to both apps (hide auth loading flash)
- Introduce constants/enums across entire codebase (no raw string literals)
- Move price tiers from hardcoded array to app_config DB (data-driven, includes 1-min test tier)
- Add session ownership validation on all shared chat routes
- Add ownership checks on endSession, respondToExtension, requestExtension
- Fix session timer: auto-complete expired/stale sessions on server restart
- Add 5-min grace period for abandoned closing sessions
- Fix extension flow: proper session_resumed handling, clearExtensionRequest, closure grace timer cleanup
- Fix chat screens: ConnectChat in initState, session status check on connect
- Fix customer expired view: 5-min countdown, closure state priority over expired state
- Fix mitra extension UI: loading spinner, disable buttons, handle EXTENSION_RESOLVED error
- Fix GoRouter navigation consistency (no more Navigator.pushNamed)
- Fix goodbye view keyboard overflow (SingleChildScrollView)
- Add active session card on customer home screen with refresh on navigate back
- Fix PricingBottomSheet extension mode (RequestExtension instead of new pairing)
- Send session_resumed to both parties on extension accept

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

mitra_app/lib/features/chat/screens/mitra_chat_screen.dart

@@ -4,6 +4,7 @@ import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:go_router/go_router.dart';
 import '../../../core/chat/mitra_chat_bloc.dart';
 import '../../../core/chat/extension_bloc.dart';
+import '../../../core/constants.dart';
 
 class MitraChatScreen extends StatefulWidget {
   final String sessionId;
@@ -20,8 +21,15 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
   final _scrollController = ScrollController();
   Timer? _typingThrottle;
 
+  @override
+  void initState() {
+    super.initState();
+    context.read<MitraChatBloc>().add(ConnectChat(widget.sessionId));
+  }
+
   @override
   void dispose() {
+    context.read<MitraChatBloc>().add(DisconnectChat());
     _messageController.dispose();
     _scrollController.dispose();
     _typingThrottle?.cancel();
@@ -63,7 +71,7 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
             if (state is ChatConnected) {
               _scrollToBottom();
               final unread = state.messages
-                  .where((m) => m.senderType == 'customer' && m.status != 'read')
+                  .where((m) => m.senderType == UserType.customer && m.status != MessageStatus.read)
                   .map((m) => m.id)
                   .toList();
               if (unread.isNotEmpty) {
@@ -147,7 +155,7 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
             itemCount: state.messages.length,
             itemBuilder: (context, index) {
               final msg = state.messages[index];
-              final isMe = msg.senderType == 'mitra';
+              final isMe = msg.senderType == UserType.mitra;
               return _buildMessageBubble(msg, isMe);
             },
           ),
@@ -204,11 +212,11 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
     switch (status) {
       case 'sending':
         return const Icon(Icons.access_time, size: 14, color: Colors.grey);
-      case 'sent':
+      case MessageStatus.sent:
         return const Icon(Icons.check, size: 14, color: Colors.grey);
-      case 'delivered':
+      case MessageStatus.delivered:
         return const Icon(Icons.done_all, size: 14, color: Colors.grey);
-      case 'read':
+      case MessageStatus.read:
         return const Icon(Icons.done_all, size: 14, color: Colors.blue);
       default:
         return const SizedBox.shrink();
@@ -249,56 +257,64 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
     final duration = request['duration_minutes'] as int?;
     final extensionId = request['extension_id'] as String?;
 
-    return Center(
-      child: Padding(
-        padding: const EdgeInsets.all(32),
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: [
-            const Icon(Icons.timer, size: 64, color: Colors.orange),
-            const SizedBox(height: 16),
-            const Text('Permintaan Perpanjangan', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
-            const SizedBox(height: 8),
-            Text('Customer ingin perpanjang $duration menit', textAlign: TextAlign.center),
-            const SizedBox(height: 24),
-            Row(
+    return BlocBuilder<ExtensionBloc, ExtensionState>(
+      builder: (context, extState) {
+        final isResponding = extState is ExtensionResponding;
+
+        return Center(
+          child: Padding(
+            padding: const EdgeInsets.all(32),
+            child: Column(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
-                ElevatedButton(
-                  style: ElevatedButton.styleFrom(backgroundColor: Colors.green),
-                  onPressed: () => context.read<ExtensionBloc>().add(RespondToExtension(
-                    sessionId: widget.sessionId,
-                    extensionId: extensionId!,
-                    accepted: true,
-                  )),
-                  child: const Text('Terima', style: TextStyle(color: Colors.white)),
-                ),
-                const SizedBox(width: 16),
-                ElevatedButton(
-                  style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
-                  onPressed: () => context.read<ExtensionBloc>().add(RespondToExtension(
-                    sessionId: widget.sessionId,
-                    extensionId: extensionId!,
-                    accepted: false,
-                  )),
-                  child: const Text('Tolak', style: TextStyle(color: Colors.white)),
-                ),
+                const Icon(Icons.timer, size: 64, color: Colors.orange),
+                const SizedBox(height: 16),
+                const Text('Permintaan Perpanjangan', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
+                const SizedBox(height: 8),
+                Text('Customer ingin perpanjang $duration menit', textAlign: TextAlign.center),
+                const SizedBox(height: 24),
+                if (isResponding)
+                  const CircularProgressIndicator()
+                else
+                  Row(
+                    mainAxisAlignment: MainAxisAlignment.center,
+                    children: [
+                      ElevatedButton(
+                        style: ElevatedButton.styleFrom(backgroundColor: Colors.green),
+                        onPressed: extensionId == null ? null : () => context.read<ExtensionBloc>().add(RespondToExtension(
+                          sessionId: widget.sessionId,
+                          extensionId: extensionId,
+                          accepted: true,
+                        )),
+                        child: const Text('Terima', style: TextStyle(color: Colors.white)),
+                      ),
+                      const SizedBox(width: 16),
+                      ElevatedButton(
+                        style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
+                        onPressed: extensionId == null ? null : () => context.read<ExtensionBloc>().add(RespondToExtension(
+                          sessionId: widget.sessionId,
+                          extensionId: extensionId,
+                          accepted: false,
+                        )),
+                        child: const Text('Tolak', style: TextStyle(color: Colors.white)),
+                      ),
+                    ],
+                  ),
               ],
             ),
-          ],
-        ),
-      ),
+          ),
+        );
+      },
     );
   }
 
   Widget _buildGoodbyeView(BuildContext context, ExtensionState extState) {
     final controller = TextEditingController();
-    return Center(
-      child: Padding(
-        padding: const EdgeInsets.all(32),
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: [
+    return SingleChildScrollView(
+      padding: const EdgeInsets.all(32),
+      child: Column(
+        children: [
+          const SizedBox(height: 48),
             const Icon(Icons.waving_hand, size: 64, color: Colors.amber),
             const SizedBox(height: 16),
             const Text('Pesan Penutup', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
@@ -331,7 +347,6 @@ class _MitraChatScreenState extends State<MitraChatScreen> {
             ),
           ],
         ),
-      ),
     );
   }
 }