refactor: remove Redis dependency and related code

backend/app/main.py

@@ -7,7 +7,6 @@ from api.editor.router import router as editor_router
 from api.proxy.router import router as proxy_router
 from core.config import settings
 from core.mongodb import close_mongodb, init_mongodb
-from core.redis import close_redis, init_redis
 from core.security import hash_password
 from fastapi import FastAPI
 from integrations.docker import get_all_services_in_dir
@@ -21,7 +20,6 @@ from services.mitmproxy.recovery import reconcile_runtime
 @asynccontextmanager
 async def lifespan(_: FastAPI):
     await init_mongodb()
-    await init_redis()
     await ensure_auth_indexes()
     await ensure_single_account(
         username=settings.AUTH_USERNAME,
@@ -56,7 +54,6 @@ async def lifespan(_: FastAPI):
     try:
         yield
     finally:
-        await close_redis()
         await close_mongodb()