Fix HF start: run worker as module + health server

start.sh

@@ -1,8 +1,4 @@
 #!/usr/bin/env sh
 set -eu
-
-# Start the worker (must be module so relative imports work)
 python -u -m backend.worker.worker &
-
-# Health server (HF needs a listening web process)
 exec uvicorn health_api:app --host 0.0.0.0 --port "${PORT:-7860}"