docs(code): add concise docstrings

src/gapido_auth/infrastructure/container.py

@@ -19,12 +19,16 @@ from gapido_auth.infrastructure.sms_provider import get_sms_template
 
 @dataclass(slots=True)
 class AppContainer:
+    """Runtime dependencies that need explicit shutdown after the gRPC server stops."""
+
     auth_service: AuthService
     mongo_client: AsyncIOMotorClient[Any]
     redis: Redis
 
 
 async def build_auth_service(settings: Settings, rabbitmq_channel: AbstractChannel) -> AppContainer:
+    """Create repositories, adapters, policies, and the AuthService use-case object."""
+
     mongo_client: AsyncIOMotorClient[Any] = AsyncIOMotorClient(settings.mongo_uri)
     db = mongo_client[settings.mongo_db_name]
     users = MongoUserRepository(db)