refactor: 统一 Redis 连接管理，改用 RedisService

- App 启动时初始化 RedisService，关闭时释放连接
- Celery worker 通过 worker_process_init 钩子初始化 Redis
- Agent 端点改用 RedisService 替代直接创建连接
- Celery task 改为 async def，使用统一连接
- 删除无用的 infra 模块和 core/http/models
- 日志脱敏，不记录 Redis 密码
- 初始化失败时 fail-fast
- 异常发布添加二级保护

backend/src/v1/agent/dependencies.py

@@ -4,21 +4,20 @@ from typing import Any, cast
 from uuid import UUID
 
 from fastapi import Depends
-import redis.asyncio as redis
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from core.agent.infrastructure.events.redis_stream import RedisStreamEventStore
 from core.agent.infrastructure.queue.tasks import run_command_task
 from core.config.settings import config
 from core.db import get_db
+from services.base.redis import redis_service
 from v1.agent.repository import AgentRepository
 from v1.agent.service import AgentService
 
 
 class CeleryQueueClient:
     def __init__(self) -> None:
-        settings = cast(Any, config)
-        self._redis = redis.from_url(settings.redis.url, decode_responses=True)
+        self._redis = redis_service.get_client()
 
     async def enqueue(
         self, *, command: dict[str, object], dedup_key: str | None
@@ -46,7 +45,7 @@ class CeleryQueueClient:
 class RedisEventStream:
     def __init__(self) -> None:
         settings = cast(Any, config)
-        client = redis.from_url(settings.redis.url, decode_responses=True)
+        client = redis_service.get_client()
         self._store = RedisStreamEventStore(
             client=client,
             stream_prefix=settings.agent_runtime.redis_stream_prefix,