refactor(api): TOML 配置 SSOT、统一错误契约、Auth/事务加固与可观测性 (#33)

配置 SSOT（TOML + .env）
统一错误契约
Auth 与事务边界
Redis / Celery 可靠性:业务 Redis（DB/0）与 Celery broker/backend（DB/1）显式拆分；连接池、sync client
可观测性（OpenTelemetry + LGTM）

api/app/features/auth/deps.py

@@ -1,16 +1,17 @@
 """Auth feature dependencies: get_auth_service."""
 
 from fastapi import Depends
-from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.db import get_async_db
-from app.core.dependencies import get_sms_sender
+from app.core.dependencies import get_object_storage, get_sms_sender
+from app.core.deps_types import DbDep
 from app.features.auth.service import AuthService
 from app.ports.sms import SmsSender
+from app.ports.storage import ObjectStorage
 
 
 def get_auth_service(
-    db: AsyncSession = Depends(get_async_db),
+    db: DbDep,
     sms: SmsSender = Depends(get_sms_sender),
+    object_storage: ObjectStorage = Depends(get_object_storage),
 ) -> AuthService:
-    return AuthService(db=db, sms=sms)
+    return AuthService(db=db, sms=sms, object_storage=object_storage)