refactor(apps): 主题系统迁移至 ColorScheme + 扩展架构并支持 Dark Mode

apps/lib/core/config/env.dart

@@ -1,5 +1,7 @@
 import 'dart:io';
 
+import 'package:package_info_plus/package_info_plus.dart';
+
 class Env {
   static String get apiUrl {
     final backendUrl = const String.fromEnvironment('BACKEND_URL');
@@ -11,4 +13,14 @@ class Env {
     }
     return 'http://localhost:5775';
   }
+
+  static String version = '0.1.0';
+  static int build = 1;
+
+  static Future<void> init() async {
+    final info = await PackageInfo.fromPlatform();
+    version = info.version;
+    final buildStr = info.buildNumber.isEmpty ? '1' : info.buildNumber;
+    build = int.tryParse(buildStr) ?? 1;
+  }
 }