Add Node.js for Gradio SSR build, bind to 0.0.0.0:7860

Gradio 6 hangs without Node.js. Also explicitly set server_name
and server_port for Docker SDK compatibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -1,6 +1,8 @@
 FROM python:3.12-slim
 
-RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y git curl && rm -rf /var/lib/apt/lists/*
+RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - && \
+    apt-get install -y nodejs && rm -rf /var/lib/apt/lists/*
 
 RUN useradd -m -u 1000 user
 WORKDIR /app

app.py

@@ -647,4 +647,4 @@ WORKSPACE_DIR = load_workspace()
 
 if __name__ == "__main__":
     demo = build_app()
-    demo.launch(ssr_mode=False)
+    demo.launch(ssr_mode=False, server_name="0.0.0.0", server_port=7860)