feat(notification): 通知标题和正文支持多语言

- 通知静态配置支持 title/body i18n
- 前端通知列表和详情页展示本地化内容
- 新增数据库迁移脚本
- 更新通知协议文档

apps/lib/features/notifications/presentation/screens/notification_center_screen.dart

@@ -2,7 +2,9 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 
+import '../../../../l10n/app_localizations.dart';
 import '../../../../shared/theme/design_tokens.dart';
+import '../../../../shared/widgets/app_loading_indicator.dart';
 import '../../../../shared/widgets/notification/notification_detail_bottom_sheet.dart';
 import '../../data/models/notification_item.dart';
 import '../../data/models/notification_payload.dart';
@@ -31,54 +33,93 @@ class NotificationCenterScreen extends StatefulWidget {
 }
 
 class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
-  late NotificationBloc _bloc;
+  NotificationBloc? _bloc;
+  late final ScrollController _scrollController;
+
+  String get _currentLocale {
+    final locale = Localizations.localeOf(context);
+    if (locale.scriptCode == 'Hant') return 'zh_Hant';
+    return locale.languageCode;
+  }
 
   @override
   void initState() {
     super.initState();
-    _bloc = NotificationBloc(repository: widget.repository);
-    _bloc.handleEvent(LoadNotifications());
-    _bloc.addListener(_onStateChanged);
+    _scrollController = ScrollController()..addListener(_onScroll);
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    if (_bloc == null) {
+      _bloc = NotificationBloc(
+        repository: widget.repository,
+        locale: _currentLocale,
+      );
+      _bloc!.handleEvent(LoadNotifications());
+      _bloc!.addListener(_onStateChanged);
+    }
   }
 
   void _onStateChanged() {
     setState(() {});
   }
 
+  void _onScroll() {
+    if (!_scrollController.hasClients || _bloc == null) return;
+    final position = _scrollController.position;
+    if (position.pixels >= position.maxScrollExtent - 240) {
+      unawaited(_bloc!.handleEvent(LoadMoreNotifications()));
+    }
+  }
+
   @override
   void dispose() {
-    _bloc.removeListener(_onStateChanged);
-    _bloc.dispose();
+    _bloc?.removeListener(_onStateChanged);
+    _bloc?.dispose();
+    _scrollController.removeListener(_onScroll);
+    _scrollController.dispose();
     super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
     final colors = Theme.of(context).colorScheme;
-    final state = _bloc.state;
+    final l10n = AppLocalizations.of(context)!;
+    final state = _bloc!.state;
 
     return Scaffold(
+      backgroundColor: colors.surfaceContainerLow,
       appBar: AppBar(
-        title: const Text('通知'),
+        title: Text(l10n.notifyCenterTitle),
         centerTitle: true,
+        backgroundColor: colors.surfaceContainerLow,
+        surfaceTintColor: colors.surfaceContainerLow,
         actions: [
           if (state.items.any((item) => !item.isRead))
             TextButton(
               onPressed: _onMarkAllRead,
-              child: Text('全部已读', style: TextStyle(color: colors.primary)),
+              child: Text(
+                l10n.notifyMarkAllRead,
+                style: TextStyle(color: colors.primary),
+              ),
             ),
         ],
       ),
       body: RefreshIndicator(
-        onRefresh: () => _bloc.handleEvent(RefreshNotifications()),
-        child: _buildBody(state, colors),
+        onRefresh: () => _bloc!.handleEvent(RefreshNotifications()),
+        child: _buildBody(state, colors, l10n),
       ),
     );
   }
 
-  Widget _buildBody(NotificationState state, ColorScheme colors) {
+  Widget _buildBody(
+    NotificationState state,
+    ColorScheme colors,
+    AppLocalizations l10n,
+  ) {
     if (state.status == NotificationStatus.loading && state.items.isEmpty) {
-      return const Center(child: CircularProgressIndicator());
+      return const Center(child: AppLoadingIndicator());
     }
 
     if (state.status == NotificationStatus.error && state.items.isEmpty) {
@@ -88,11 +129,14 @@ class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
           children: [
             Icon(Icons.error_outline, size: 48, color: colors.error),
             const SizedBox(height: AppSpacing.md),
-            Text('加载失败', style: TextStyle(color: colors.onSurfaceVariant)),
+            Text(
+              l10n.notifyLoadFailed,
+              style: TextStyle(color: colors.onSurfaceVariant),
+            ),
             const SizedBox(height: AppSpacing.sm),
             FilledButton(
-              onPressed: () => _bloc.handleEvent(LoadNotifications()),
-              child: const Text('重试'),
+              onPressed: () => _bloc!.handleEvent(LoadNotifications()),
+              child: Text(l10n.notifyRetry),
             ),
           ],
         ),
@@ -115,7 +159,7 @@ class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
                   ),
                   const SizedBox(height: AppSpacing.md),
                   Text(
-                    '暂无通知',
+                    l10n.notifyEmpty,
                     style: TextStyle(
                       color: colors.onSurfaceVariant,
                       fontSize: 16,
@@ -130,13 +174,13 @@ class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
     }
 
     return ListView.builder(
+      controller: _scrollController,
       itemCount: state.items.length + (state.hasMore ? 1 : 0),
       itemBuilder: (context, index) {
         if (index == state.items.length && state.hasMore) {
-          _bloc.handleEvent(LoadMoreNotifications());
           return const Padding(
             padding: EdgeInsets.all(AppSpacing.lg),
-            child: Center(child: CircularProgressIndicator()),
+            child: Center(child: AppLoadingIndicator()),
           );
         }
         final item = state.items[index];
@@ -154,11 +198,13 @@ class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
   ) async {
     final wasUnread = !item.isRead;
     if (!item.isRead) {
-      await _bloc.handleEvent(MarkNotificationRead(notificationId: item.id));
-      final updatedIndex = _bloc.state.items.indexWhere((n) => n.id == item.id);
+      await _bloc!.handleEvent(MarkNotificationRead(notificationId: item.id));
+      final updatedIndex = _bloc!.state.items.indexWhere(
+        (n) => n.id == item.id,
+      );
       if (wasUnread &&
           updatedIndex >= 0 &&
-          _bloc.state.items[updatedIndex].isRead) {
+          _bloc!.state.items[updatedIndex].isRead) {
         await widget.onUnreadCountChanged?.call();
       }
     }
@@ -188,9 +234,9 @@ class _NotificationCenterScreenState extends State<NotificationCenterScreen> {
   }
 
   Future<void> _markAllRead() async {
-    final unreadBefore = _bloc.state.items.any((item) => !item.isRead);
-    await _bloc.handleEvent(MarkAllNotificationsRead());
-    final unreadAfter = _bloc.state.items.any((item) => !item.isRead);
+    final unreadBefore = _bloc!.state.items.any((item) => !item.isRead);
+    await _bloc!.handleEvent(MarkAllNotificationsRead());
+    final unreadAfter = _bloc!.state.items.any((item) => !item.isRead);
     if (unreadBefore && !unreadAfter) {
       await widget.onUnreadCountChanged?.call();
     }