Update Dockerfile

Dockerfile

@@ -61,7 +61,8 @@ RUN mkdir -p /cache/hf /tmp && chmod -R 777 /cache /tmp
 EXPOSE 7860
 
 HEALTHCHECK --interval=30s --timeout=10s --retries=3 \
-  CMD curl -fsS "http://127.0.0.1:${PORT}/health/" || exit 1
+  CMD curl -fsS "http://127.0.0.1:${PORT:-7860}/health/" || exit 1
 
 # ✅ bind to $PORT provided by HF; include proxy headers
-CMD ["sh","-c","uvicorn backend:app --host 0.0.0.0 --port ${PORT} --proxy-headers --forwarded-allow-ips='*'"]
+CMD ["sh","-c","uvicorn backend:app --host 0.0.0.0 --port ${PORT:-7860} --proxy-headers --forwarded-allow-ips='*'"]
+