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_ai/chat/controller.py

@@ -9,7 +9,7 @@ from redis.asyncio import Redis
 from app.common.response import ResponseSchema, SuccessResponse
 from app.core.base_schema import AuthSchema, PaginationQueryParam
 from app.core.database import async_db_session
-from app.core.dependencies import AuthPermission, _authenticate, redis_getter
+from app.core.dependencies import AuthPermission, _authenticate, require_redis
 from app.core.exceptions import CustomException
 from app.core.logger import logger
 from app.core.router_class import OperationLogRoute
@@ -110,7 +110,7 @@ async def ai_chat_controller(
 
 @ChatRouter.get("/model", summary="获取 AI 模型配置列表", response_model=ResponseSchema[AiModelConfigListResponse])
 async def list_model_config_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     auth: Annotated[AuthSchema, Security(AuthPermission(["module_ai:chat:query"]))],
 ) -> JSONResponse:
     service = AiModelConfigService(auth, redis)
@@ -120,7 +120,7 @@ async def list_model_config_controller(
 
 @ChatRouter.post("/model", status_code=status.HTTP_201_CREATED, summary="新增一个 AI 模型配置", response_model=ResponseSchema[dict[str, Any]])
 async def create_model_config_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     auth: Annotated[AuthSchema, Security(AuthPermission(["module_ai:chat:update"]))],
     data: Annotated[AiModelConfigUpdateSchema, Body(description="模型配置参数")],
 ) -> JSONResponse:
@@ -132,7 +132,7 @@ async def create_model_config_controller(
 
 @ChatRouter.put("/model/{config_id}", summary="更新指定 ID 的 AI 模型配置", response_model=ResponseSchema[dict[str, Any]])
 async def update_model_config_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     auth: Annotated[AuthSchema, Security(AuthPermission(["module_ai:chat:update"]))],
     config_id: Annotated[str, Path(description="配置项 ID")],
     data: Annotated[AiModelConfigUpdateSchema, Body(description="模型配置参数")],
@@ -145,7 +145,7 @@ async def update_model_config_controller(
 
 @ChatRouter.delete("/model/{config_id}", summary="删除指定 ID 的 AI 模型配置", response_model=ResponseSchema[None])
 async def delete_model_config_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     auth: Annotated[AuthSchema, Security(AuthPermission(["module_ai:chat:update"]))],
     config_id: Annotated[str, Path(description="配置项 ID")],
 ) -> JSONResponse:
@@ -156,7 +156,7 @@ async def delete_model_config_controller(
 
 @ChatRouter.post("/model/{config_id}/activate", summary="切换激活的 AI 模型配置", response_model=ResponseSchema[None])
 async def activate_model_config_controller(
-    redis: Annotated[Redis, Depends(redis_getter)],
+    redis: Annotated[Redis, Depends(require_redis)],
     auth: Annotated[AuthSchema, Security(AuthPermission(["module_ai:chat:update"]))],
     config_id: Annotated[str, Path(description="配置项 ID；传 __default__ 使用系统默认")],
 ) -> JSONResponse: