feat(locale): 实现 App 启动时语言和时区自动设置

- 新增系统语言/时区读取工具函数
- SessionStore 扩展支持时区存储
- 启动流程自动检测并保存系统语言/时区
- 注册时传递语言/时区到后端
- 登录后从服务器同步语言/时区

backend/src/v1/auth/router.py

@@ -22,6 +22,7 @@ from v1.auth.schemas import (
 from v1.auth.service import AuthService
 from v1.points.repository import PointsRepository
 from v1.points.service import PointsService
+from v1.users.repository import SQLAlchemyUserRepository
 
 
 router = APIRouter(prefix="/auth", tags=["auth"])
@@ -72,14 +73,30 @@ async def create_email_session(
         window_seconds=300,
     )
     result = await service.create_email_session(payload)
+    user_id = UUID(result.user.id)
+
+    if payload.language is not None or payload.timezone is not None:
+        user_repository = SQLAlchemyUserRepository(session)
+        profile = await user_repository.get_profile_by_user_id(user_id=user_id)
+        if profile is not None:
+            settings: dict[str, object] = dict(profile.settings or {})
+            prefs_raw = settings.get("preferences", {})
+            preferences: dict[str, object] = dict(prefs_raw) if isinstance(prefs_raw, dict) else {}
+            if payload.language is not None:
+                preferences["language"] = payload.language
+            if payload.timezone is not None:
+                preferences["timezone"] = payload.timezone
+            settings["preferences"] = preferences
+            profile.settings = settings
+
     points_service = PointsService(repository=PointsRepository(session))
     bonus_result = await points_service.grant_register_bonus_if_eligible(
-        user_id=UUID(result.user.id),
+        user_id=user_id,
         user_email=result.user.email,
     )
     notification_service = NotificationService(NotificationRepository(session))
     linked_count = await notification_service.link_notifications_for_registered_user(
-        user_id=UUID(result.user.id),
+        user_id=user_id,
         is_first_registration=bonus_result.is_first_registration,
     )
     await session.commit()

backend/src/v1/auth/schemas.py

@@ -17,6 +17,8 @@ class EmailSessionCreateRequest(BaseModel):
 
     email: str = Field(pattern=SUPABASE_EMAIL_PATTERN)
     token: str = Field(min_length=6, max_length=6)
+    language: str | None = Field(default=None, max_length=20)
+    timezone: str | None = Field(default=None, max_length=50)
 
 
 class SessionRefreshRequest(BaseModel):