fix(docker): override base ENTRYPOINT to run start.py (enable Gradio UI)

Dockerfile

@@ -52,7 +52,4 @@ HEALTHCHECK --interval=30s --timeout=3s --start-period=10s --retries=3 \
 # Hugging Face Spaces expect public app on port 7860
 ENV PORT=7860
 EXPOSE 7860
-
-RUN echo "==== DEBUG LISTING /app ====" && ls -R /app
-# Unified startup script
-CMD ["python", "start.py"]
+ENTRYPOINT ["python", "-u", "start.py"]