Bake GPU/IPFS settings into Dockerfile

Settings in Dockerfile override swarm service env vars.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile.gpu

@@ -39,6 +39,10 @@ ENV PYTHONUNBUFFERED=1
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV EFFECTS_PATH=/app/artdag-effects
 ENV PYTHONPATH=/app
+# GPU persistence disabled until all primitives support GPU frames
+ENV STREAMING_GPU_PERSIST=0
+# Use cluster's public IPFS gateway for HLS segment URLs
+ENV IPFS_GATEWAY_URL=https://celery-artdag.rose-ash.com/ipfs
 
 # Default command runs celery worker
 CMD ["celery", "-A", "celery_app", "worker", "--loglevel=info", "-E", "-Q", "gpu,celery"]