fix: use relative paths for STAGING_ROOT and LOG_DIR so backend works on host regardless of install location

backend/app.py

@@ -41,7 +41,7 @@ _ch.setFormatter(logging.Formatter("%(asctime)s %(levelname)s %(message)s"))
 logger.addHandler(_ch)
 
 # File handler → shared log directory
-LOG_DIR = Path("/mnt/converter/logs")
+LOG_DIR = Path(__file__).resolve().parent.parent / "logs"
 LOG_DIR.mkdir(parents=True, exist_ok=True)
 _fh = RotatingFileHandler(
     LOG_DIR / "vm-bench-backend.log", maxBytes=10 * 1024 * 1024, backupCount=5,

backend/converter.py

@@ -15,7 +15,7 @@ from pathlib import Path
 from dataclasses import dataclass
 from typing import Optional
 
-STAGING_ROOT = Path("/mnt/converter/tmp")
+STAGING_ROOT = Path(__file__).resolve().parent.parent / "tmp"
 STAGING_IN = STAGING_ROOT / "in"
 
 logger = logging.getLogger("backend.converter")

backend/provisioner.py

@@ -30,7 +30,7 @@ from converter import extract_if_needed, discover_disk, detect_efi
 
 logger = logging.getLogger("backend.provisioner")
 
-STAGING_ROOT = Path("/mnt/converter/tmp")
+STAGING_ROOT = Path(__file__).resolve().parent.parent / "tmp"
 STAGING_IN = STAGING_ROOT / "in"
 STAGING_OUT = STAGING_ROOT / "out"