Update Dockerfile

Dockerfile

@@ -13,4 +13,13 @@ COPY app.py .
 
 EXPOSE 7860
 
-CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "7860"]
+HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
+    CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:7860/health')"
+
+# Shell form so $WEB_CONCURRENCY is expanded at runtime (set to 4 in HF Spaces)
+# uvicorn.workers.UvicornWorker = correct ASGI worker class for FastAPI + Gunicorn
+CMD gunicorn app:app \
+    --workers ${WEB_CONCURRENCY:-4} \
+    --bind 0.0.0.0:7860 \
+    --timeout 120 \
+    --worker-class uvicorn.workers.UvicornWorker