feat: add two-tab timetable UI and glass dock

mobile/lib/app/app_controller.dart

@@ -2,7 +2,6 @@ import 'package:flutter/foundation.dart';
 
 import '../domain/app_snapshot.dart';
 import '../domain/app_settings.dart';
-import '../domain/course.dart';
 import '../data/snapshot_store.dart';
 import '../data/json_schedule_import.dart';
 import '../services/notification_service.dart';
@@ -29,6 +28,9 @@ class AppController extends ChangeNotifier {
       isDemo ? _demoSettings! : snapshot.settings;
   Future<void> _run(Future<void> Function() operation) {
     final next = _queue.then((_) async {
+      if (storageReady) {
+        lastError = null;
+      }
       try {
         await operation();
       } catch (error) {
@@ -84,14 +86,16 @@ class AppController extends ChangeNotifier {
     isDemo = false;
   });
   Future<void> updateSettings(AppSettings value) => _run(() async {
-    if (![5, 10, 15, 30, 60].contains(value.reminderMinutes))
+    if (![5, 10, 15, 30, 60].contains(value.reminderMinutes)) {
       throw ArgumentError('提醒时间无效');
+    }
     await _save(snapshot.copyWith(settings: value));
-    if (isDemo)
+    if (isDemo) {
       _demoSettings = _demoSettings!.copyWith(
         colorMode: value.colorMode,
         singleColorArgb: value.singleColorArgb,
       );
+    }
     await _reconcile();
   });
   Future<void> applyImport(
@@ -101,8 +105,9 @@ class AppController extends ChangeNotifier {
     if (draft.courses.isEmpty && (!draft.explicitlyEmpty || !confirmedEmpty)) {
       throw const FormatException('未检测到课程，已有课表保持不变');
     }
-    if (draft.courses.map((c) => c.id).toSet().length != draft.courses.length)
+    if (draft.courses.map((c) => c.id).toSet().length != draft.courses.length) {
       throw const FormatException('课程标识重复');
+    }
     if (draft.source == CourseSource.demo) {
       _demo = draft.courses;
       isDemo = true;
@@ -117,8 +122,9 @@ class AppController extends ChangeNotifier {
       );
       return;
     }
-    if (draft.courses.any((c) => c.source != draft.source))
+    if (draft.courses.any((c) => c.source != draft.source)) {
       throw const FormatException('课程来源不一致');
+    }
     await _save(
       snapshot.copyWith(
         courses: draft.courses,
@@ -195,6 +201,9 @@ class AppController extends ChangeNotifier {
   });
   Future<void> refreshServices() => _run(_reconcile);
   Future<void> _reconcile() async {
+    if (!storageReady) {
+      return;
+    }
     final settings = snapshot.settings;
     final occurrences = settings.semester == null
         ? <CourseOccurrence>[]