feat: 集成 Apple Sign-In + iOS 上线准备

- 后端新增 Apple 登录端点 /api/auth/apple-login
- 新增 AppleTokenValidator 验证 IdentityToken
- User 实体添加 AppleUserId 字段，Phone 改为可空
- 前端添加 sign_in_with_apple 依赖和 Apple 登录按钮
- 统一 Bundle ID 为 com.datalumina.YYA，显示名称为小脉健康
- 配置 DEVELOPMENT_TEAM 和 Sign in with Apple Entitlements
- 补充 NSCamera/NSPhotoLibrary 权限描述
- 生产 API 地址改为 https://erpapi.datalumina.cn/xiaomai
- Flutter 升级至 3.44.6 / Dart 3.12.2

Co-Authored-By: Claude <noreply@anthropic.com>

health_app/ios/Podfile.lock

@@ -0,0 +1,22 @@
+PODS:
+  - Flutter (1.0.0)
+  - sign_in_with_apple (0.0.1):
+    - Flutter
+
+DEPENDENCIES:
+  - Flutter (from `Flutter`)
+  - sign_in_with_apple (from `.symlinks/plugins/sign_in_with_apple/ios`)
+
+EXTERNAL SOURCES:
+  Flutter:
+    :path: Flutter
+  sign_in_with_apple:
+    :path: ".symlinks/plugins/sign_in_with_apple/ios"
+
+SPEC CHECKSUMS:
+  Flutter: cabc95a1d2626b1b06e7179b784ebcf0c0cde467
+  sign_in_with_apple: c5dcc141574c8c54d5ac99dd2163c0c72ad22418
+
+PODFILE CHECKSUM: 261798c42a06ff769f68b1209723cd96e5586217
+
+COCOAPODS: 1.16.2