feat: 添加环境枚举和兼容性处理，优化 H5 线路配置

lib/config/app_config.dart

@@ -12,6 +12,12 @@ class H5Line {
   Uri get uri => Uri.parse(url);
 }
 
+enum Environment {
+  development,
+  staging,
+  production,
+}
+
 class AppConfig {
   static const String appName = '本地打包';
   static const String appLogo = '';
@@ -25,11 +31,19 @@ class AppConfig {
   static const String _bootstrapH5LineUrl = String.fromEnvironment(
       'BOOTSTRAP_H5_LINE_URL',
       defaultValue: 'https://h5-test.imharry.work/');
+  static const Environment currentEnvironment = Environment.production;
+  // Compatibility for the packaging service's legacy domain rewrite step.
+  static final Map<Environment, List<String>> _environmentHosts = {
+    Environment.production: [
+      _bootstrapH5LineUrl,
+    ],
+  };
   static final Random _wildcardRandom = Random.secure();
 
   static List<H5Line> get h5Lines {
     final configuredUrls = _dartDefinedH5LineUrls.trim().isEmpty
-        ? _normalizedUniqueUrls(const [_bootstrapH5LineUrl])
+        ? _normalizedUniqueUrls(_environmentHosts[currentEnvironment] ??
+            const [_bootstrapH5LineUrl])
         : _normalizedUniqueUrls(_dartDefinedH5LineUrls.split(','));
     final urls = configuredUrls.isEmpty
         ? _normalizedUniqueUrls(const [_bootstrapH5LineUrl])