feat: 新人初始礼包购买追踪功能

- 数据库：添加 has_purchased_starter_pack 字段到 register_bonus_claims
- 后端：创建静态配置管理套餐信息，支持按国家/地区区分
- 后端：新增 GET /api/v1/points/packages API 返回可用套餐
- 后端：创建 utils/paths.py 统一路径管理
- 前端：动态获取套餐信息，移除硬编码
- 前端：添加 ProductCode 枚举约束，前后端类型安全
- 配置：Profile 默认国家改为 US（ISO 3166-1 alpha-2）
- 文档：更新协议文档说明新 API 和字段

apps/lib/features/settings/presentation/screens/coin_center_screen.dart

@@ -1,15 +1,66 @@
 import 'package:flutter/material.dart';
 
+import '../../../../app/di/injection.dart';
+import '../../../../core/auth/session_store.dart';
+import '../../../../core/logging/logger.dart';
+import '../../../../data/network/api_client.dart';
+import '../../../../data/storage/local_kv_store.dart';
 import '../../../../l10n/app_localizations.dart';
 import '../../../../shared/theme/app_color_palette.dart';
 import '../../../../shared/theme/design_tokens.dart';
+import '../../../points/data/apis/points_api.dart';
+import '../../../points/data/models/package_info.dart';
 import '../widgets/settings_section_widgets.dart';
 
-class CoinCenterScreen extends StatelessWidget {
+class CoinCenterScreen extends StatefulWidget {
   const CoinCenterScreen({super.key, required this.balance});
 
   final int balance;
 
+  @override
+  State<CoinCenterScreen> createState() => _CoinCenterScreenState();
+}
+
+class _CoinCenterScreenState extends State<CoinCenterScreen> {
+  final Logger _logger = getLogger('features.settings.coin_center_screen');
+  List<PackageInfo>? _packages;
+  bool _isLoading = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadPackages();
+  }
+
+  Future<void> _loadPackages() async {
+    try {
+      final sessionStore = SessionStore(LocalKvStore());
+      final apiClient = ApiClient(
+        baseUrl: appDependencies.backendUrl,
+        tokenProvider: sessionStore.getToken,
+      );
+      final api = PointsApi(apiClient.rawDio);
+      final result = await api.getPackages();
+      if (mounted) {
+        setState(() {
+          _packages = result.packages;
+          _isLoading = false;
+        });
+      }
+    } catch (e, stackTrace) {
+      _logger.error(
+        message: 'Failed to load packages',
+        error: e,
+        stackTrace: stackTrace,
+      );
+      if (mounted) {
+        setState(() {
+          _isLoading = false;
+        });
+      }
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context)!;
@@ -52,7 +103,7 @@ class CoinCenterScreen extends StatelessWidget {
                 ),
                 const SizedBox(height: AppSpacing.xs),
                 Text(
-                  l10n.settingsCoinBalanceValue(balance),
+                  l10n.settingsCoinBalanceValue(widget.balance),
                   style: Theme.of(
                     context,
                   ).textTheme.headlineMedium?.copyWith(color: colors.onPrimary),
@@ -69,26 +120,55 @@ class CoinCenterScreen extends StatelessWidget {
           ),
           const SizedBox(height: AppSpacing.xl),
           SectionLabel(text: l10n.settingsCoinRechargeSection),
-          CoinPackageCard(
-            title: l10n.settingsCoinPackBasic,
-            price: '\$4.99',
-            amount: 100,
-          ),
-          const SizedBox(height: AppSpacing.md),
-          CoinPackageCard(
-            title: l10n.settingsCoinPackPopular,
-            price: '\$7.99',
-            amount: 210,
-            badge: l10n.settingsCoinPackPopularBadge,
-          ),
-          const SizedBox(height: AppSpacing.md),
-          CoinPackageCard(
-            title: l10n.settingsCoinPackPremium,
-            price: '\$12.99',
-            amount: 415,
-          ),
+          ..._buildPackageCards(l10n),
         ],
       ),
     );
   }
+
+  List<Widget> _buildPackageCards(AppLocalizations l10n) {
+    if (_isLoading) {
+      return [
+        const Padding(
+          padding: EdgeInsets.all(AppSpacing.xl),
+          child: Center(child: CircularProgressIndicator()),
+        ),
+      ];
+    }
+
+    if (_packages == null || _packages!.isEmpty) {
+      return [];
+    }
+
+    return List.generate(_packages!.length, (index) {
+      final pkg = _packages![index];
+      return Column(
+        children: [
+          if (index > 0) const SizedBox(height: AppSpacing.md),
+          CoinPackageCard(
+            title: _getPackageTitle(pkg, l10n),
+            price: pkg.priceDisplay,
+            amount: pkg.credits,
+            badge: _getPackageBadge(pkg, l10n),
+          ),
+        ],
+      );
+    });
+  }
+
+  String? _getPackageBadge(PackageInfo pkg, AppLocalizations l10n) {
+    if (pkg.productCode == ProductCode.popularPack) {
+      return l10n.settingsCoinPackPopularBadge;
+    }
+    return null;
+  }
+
+  String _getPackageTitle(PackageInfo pkg, AppLocalizations l10n) {
+    return switch (pkg.productCode) {
+      ProductCode.newUserPack => l10n.settingsCoinPackStarter,
+      ProductCode.basicPack => l10n.settingsCoinPackBasic,
+      ProductCode.popularPack => l10n.settingsCoinPackPopular,
+      ProductCode.premiumPack => l10n.settingsCoinPackPremium,
+    };
+  }
 }