refactor(config): 服务地址改为 dev/prod 配置文件与单个环境开关

启动时按环回、局域网、公网顺序探测地址，换网络后会静默切到别处，排查
困难。改为代码内一个布尔开关选择环境，地址分别放在 dev_config.dart 与
prod_config.dart，不再探测；调试条改地址后直接重载，不再重新探测。
release 构建若仍是开发开关会启动即报错，避免线上包连开发机。

lib/pages/discover/discover_view.dart

@@ -10,7 +10,6 @@ import 'package:provider/provider.dart';
 import '../../core/data/models/drama.dart';
 import '../../core/data/repositories/catalog_repository.dart';
 import '../../core/data/repositories/search_repository.dart';
-import '../../core/data/services/catalog_retry.dart';
 import '../../core/data/services/category_controller.dart';
 import '../../core/data/services/theater_feed_controller.dart';
 import '../../core/formatting/error_text.dart';
@@ -408,15 +407,11 @@ class _DiscoverPageState extends State<DiscoverPage> {
   );
 
   Future<void> _retryCategories(CategoryController categories) {
-    return retryCatalogLoad(reload: categories.load);
+    return categories.load();
   }
 
-  Future<void> _retryTheater() async {
-    await retryCatalogLoad(
-      reload: () async {
-        await theater.refreshCurrent();
-      },
-    );
+  Future<void> _retryTheater() {
+    return theater.refreshCurrent();
   }
 
   Future<void> _editTheaterEndpoint() {