Replace in-memory TTL cache with Redis

routers/drives.py

@@ -1,4 +1,4 @@
-from fastapi import APIRouter, HTTPException
+from fastapi import APIRouter, HTTPException, Response
 
 from models.schemas import DriveDetail
 from services.smart import get_smart_data
@@ -8,10 +8,10 @@ router = APIRouter(prefix="/api/drives", tags=["drives"])
 
 
 @router.get("/{device}", response_model=DriveDetail)
-async def get_drive_detail(device: str):
+async def get_drive_detail(device: str, response: Response):
     """Get SMART detail for a specific block device."""
     try:
-        data = await get_smart_data(device)
+        data, cache_hit = await get_smart_data(device)
     except ValueError as e:
         raise HTTPException(status_code=400, detail=str(e))
 
@@ -25,4 +25,6 @@ async def get_drive_detail(device: str):
         data["zfs_vdev"] = zfs_info["vdev"]
         data["zfs_state"] = zfs_info.get("state")
 
+    response.headers["X-Cache"] = "HIT" if cache_hit else "MISS"
+
     return DriveDetail(**data)