feat(app): 多页面动态化 — 搜索/资料/教师/贴纸库/模板/日历

- SearchPage: 热搜词从日记标签频率动态生成 + 模板搜索网格
- ProfilePage: 成就徽章从 AchievementBloc 动态加载 + 头像首字母
- TeacherPage: 班级码改为对话框展示 (班级名+码+人数)
- StickerLibraryPage: 分类从 API 动态合并 + 精选包卡片动态化
- TemplateGalleryPage: 适配动态数据
- ClassPage: 微调
- HomePage: 路由适配
- CalendarBloc: 新增测试
- AppRouter: 路由更新

app/lib/features/teacher/views/teacher_page.dart

@@ -67,11 +67,7 @@ class _TeacherView extends StatelessWidget {
               iconColor: AppColors.tertiary,
               title: '班级码管理',
               subtitle: '查看和重置班级码',
-              onTap: () {
-                ScaffoldMessenger.of(context).showSnackBar(
-                  const SnackBar(content: Text('班级码: a1b2c3')),
-                );
-              },
+              onTap: () => _showClassCodes(context),
             ),
             const SizedBox(height: 24),
 
@@ -159,6 +155,40 @@ class _TeacherView extends StatelessWidget {
     );
   }
 
+  void _showClassCodes(BuildContext context) {
+    final classState = context.read<ClassBloc>().state;
+    final classes = classState is ClassListLoaded ? classState.classes : <SchoolClass>[];
+
+    if (classes.isEmpty) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        const SnackBar(content: Text('请先创建班级')),
+      );
+      return;
+    }
+
+    showDialog(
+      context: context,
+      builder: (dialogContext) => AlertDialog(
+        title: const Text('班级码管理'),
+        content: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: classes.map((c) => ListTile(
+            leading: const Icon(Icons.qr_code, color: AppColors.tertiary),
+            title: Text(c.name),
+            subtitle: Text('班级码: ${c.classCode} · ${c.memberCount} 人'),
+            dense: true,
+          )).toList(),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(dialogContext),
+            child: const Text('关闭'),
+          ),
+        ],
+      ),
+    );
+  }
+
   void _showAssignTopicDialog(BuildContext context) {
     final titleController = TextEditingController();
     final descController = TextEditingController();