feat(缓存): 添加本地缓存功能并优化网络状态提示

实现本地缓存管理器，支持预加载开关和排行榜数据缓存
优化网络状态提示文案和错误处理
移除调试日志打印，改进用户体验

lib/views/active/popular_page.dart

@@ -3,6 +3,7 @@ import '../../constants/app_constants.dart';
 import '../../utils/responsive_layout.dart';
 import '../../utils/http/http_client.dart';
 import '../../models/poetry_model.dart';
+import '../../controllers/load/locally.dart';
 
 /// 时间: 2026-03-25
 /// 功能: 热门页面
@@ -130,7 +131,7 @@ class _PopularPageState extends State<PopularPage>
     }
 
     return RefreshIndicator(
-      onRefresh: () async => await _loadRankList(),
+      onRefresh: () async => await _loadRankList(forceRefresh: true),
       child: NotificationListener<ScrollNotification>(
         onNotification: (scrollNotification) {
           if (scrollNotification is ScrollEndNotification &&
@@ -318,7 +319,7 @@ class _PopularPageState extends State<PopularPage>
     );
   }
 
-  Future<void> _loadRankList() async {
+  Future<void> _loadRankList({bool forceRefresh = false}) async {
     setState(() {
       _loading = true;
       _errorMessage = '';
@@ -333,6 +334,26 @@ class _PopularPageState extends State<PopularPage>
           ? 'day'
           : 'month';
 
+      final isPreloadEnabled = await LocalCacheManager().isPreloadEnabled();
+
+      if (isPreloadEnabled && !forceRefresh) {
+        print('预加载模式：尝试从本地缓存加载数据');
+        final cachedData = await LocalCacheManager().getCachedPopularList(type);
+        if (cachedData != null && cachedData.isNotEmpty) {
+          print('从本地缓存加载数据成功');
+          if (mounted) {
+            setState(() {
+              _rankList = cachedData
+                  .map((item) => PoetryModel.fromJson(item))
+                  .toList();
+              _loading = false;
+            });
+          }
+          return;
+        }
+        print('本地缓存为空，从服务器加载');
+      }
+
       print('正在请求排行榜数据: type=$type, period=$type');
 
       final response = await HttpClient.get(
@@ -349,6 +370,12 @@ class _PopularPageState extends State<PopularPage>
       if (response.isSuccess && response.code == 0) {
         final data = response.data;
         final rankData = data['list'] as List<dynamic>? ?? [];
+        final rankDataList = rankData.cast<Map<String, dynamic>>();
+
+        if (isPreloadEnabled) {
+          print('保存数据到本地缓存');
+          await LocalCacheManager().cachePopularList(type, rankDataList);
+        }
 
         if (mounted) {
           setState(() {
@@ -361,7 +388,9 @@ class _PopularPageState extends State<PopularPage>
       } else {
         if (mounted) {
           setState(() {
-            _errorMessage = response.message ?? '获取排行榜失败';
+            _errorMessage = response.message.isNotEmpty == true
+                ? response.message
+                : '获取排行榜失败';
             _loading = false;
           });
         }