checkpoint: require_redis 显式 503 守卫——存储类接口（AI配置/在线/缓存/验证码）接线

- dependencies: require_redis 改标准 FastAPI 依赖（Depends(redis_getter)），Redis 不可用显式 503 而非 500/静默空数据
- AI配置 5 端点 / 在线监控 5 端点 / 缓存监控 6 端点切到 require_redis
- 免认证验证码端点（captcha/get、slider/complete）也接线：Redis 挂时返回 503 而非 500
- login/token/oauth 保留 redis_getter（服务层内联 503 守卫语义不变）

backend/app/api/v1/module_system/auth/controller.py

@@ -30,7 +30,7 @@ from app.common.enums import EnvironmentEnum
 from app.common.response import ErrorResponse, RedirectContentResponse, ResponseSchema, SuccessResponse
 from app.config.setting import settings
 from app.core.base_schema import JWTOutSchema
-from app.core.dependencies import db_getter, get_current_user, redis_getter
+from app.core.dependencies import db_getter, get_current_user, redis_getter, require_redis
 from app.core.exceptions import CustomException
 from app.core.logger import logger
 from app.core.redis_crud import RedisCURD
@@ -90,7 +90,7 @@ async def get_new_token_controller(
 
 @AuthRouter.get("/captcha/get", summary="获取验证码", response_model=ResponseSchema[CaptchaOutSchema])
 async def get_captcha_for_login_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
 ) -> JSONResponse:
     captcha = await CaptchaService.get_captcha(redis=redis)
     return SuccessResponse(data=captcha, msg="获取验证码成功")
@@ -112,7 +112,7 @@ async def get_login_default_controller() -> JSONResponse:
 
 @AuthRouter.post("/captcha/slider/complete", summary="滑块验证完成", response_model=ResponseSchema[SliderCompleteOutSchema])
 async def slider_complete_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     body: SliderCompleteSchema,
 ) -> JSONResponse:
     result = await CaptchaService.slider_complete(redis=redis, captcha_key=body.captcha_key)