Add feedback service, reminder diagnostics and smooth week transitions

mobile/lib/app/hepan_app.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 
 import '../domain/schedule_engine.dart';
+import '../features/feedback/feedback_http_sender.dart';
+import '../features/feedback/feedback_submission.dart';
 import '../features/timetable/course_details.dart';
 
 import 'app_controller.dart';
@@ -20,11 +22,13 @@ class HepanApp extends StatelessWidget {
     this.schoolBuilder,
     this.school,
     this.notificationSelection,
+    this.feedbackSender,
   });
   final AppController controller;
   final Widget Function()? schoolBuilder;
   final SchoolSession? school;
   final ValueNotifier<String?>? notificationSelection;
+  final FeedbackSender? feedbackSender;
   @override
   Widget build(BuildContext context) => MaterialApp(
     debugShowCheckedModeBanner: false,
@@ -38,6 +42,7 @@ class HepanApp extends StatelessWidget {
       schoolBuilder: schoolBuilder,
       school: school,
       notificationSelection: notificationSelection,
+      feedbackSender: feedbackSender ?? configuredFeedbackSender(),
     ),
   );
 }
@@ -48,11 +53,13 @@ class _Shell extends StatefulWidget {
     this.schoolBuilder,
     this.school,
     this.notificationSelection,
+    required this.feedbackSender,
   });
   final AppController controller;
   final Widget Function()? schoolBuilder;
   final SchoolSession? school;
   final ValueNotifier<String?>? notificationSelection;
+  final FeedbackSender feedbackSender;
   @override
   State<_Shell> createState() => _ShellState();
 }
@@ -267,6 +274,7 @@ class _ShellState extends State<_Shell> with WidgetsBindingObserver {
                           ),
                           ProfilePage(
                             controller: widget.controller,
+                            feedbackSender: widget.feedbackSender,
                             onLogin: _school,
                             onUpdateTerm: () => _school(chooseTerm: true),
                             authStatus: widget.school?.statusLabel ?? '未登录',