fix: remove bogus SFTPStore import

backend/api.py

@@ -10,7 +10,7 @@ from fastapi import FastAPI, HTTPException, Response
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse
 from backend.sftp_store import download_bytes
-from backend.sftp_store import SFTPStore
+from backend.sftp_store import download_bytes
 
 
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