Refactor Dockerfile to streamline build process and update INSTALL_TARGET configuration

Dockerfile

@@ -1,27 +1,42 @@
 # Read the doc: https://huggingface.co/docs/hub/spaces-sdks-docker
 # you will also find guides on how best to write your Dockerfile
 
+# Configuration
+ARG GRADIO_REPO="https://github.com/Aarnonn/gradio.git"
+ARG GRADIO_BRANCH="fix/fill-height-empty-footer-12992"
+
+# Stage 1: Build frontend with Node 24
+FROM node:24 AS builder
+
+ARG GRADIO_REPO
+ARG GRADIO_BRANCH
+
+RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*
+RUN npm install -g pnpm
+
+# Clone and build Gradio
+RUN git clone --branch ${GRADIO_BRANCH} ${GRADIO_REPO} /tmp/gradio
+WORKDIR /tmp/gradio
+RUN bash scripts/build_frontend.sh
+
+# Stage 2: Runtime with Python
 FROM python:3.13
 
-# Install system utilities
-RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/*
+ARG GRADIO_REPO
+ARG GRADIO_BRANCH
+ENV INSTALL_TARGET="${GRADIO_REPO}@${GRADIO_BRANCH}"
 
 RUN useradd -m -u 1000 user
+
+# Copy compiled Gradio from builder and install
+COPY --from=builder /tmp/gradio /tmp/gradio
+WORKDIR /tmp/gradio
+RUN pip install --no-cache-dir --upgrade .
+RUN rm -rf /tmp/gradio
+
 USER user
 ENV PATH="/home/user/.local/bin:$PATH"
 
 WORKDIR /app
-
-# --- CONFIGURATION ---
-# Default is the stable 'gradio' from PyPI.
-# Replace with the .whl URL from the PR bot to test changes:
-#   1. Go to the Gradio PR on GitHub
-#   2. Find the "PR wheel preview build" check at the bottom
-#   3. Click "Details" and copy the .whl URL from the logs
-ENV INSTALL_TARGET="gradio"
-# ENV INSTALL_TARGET="git+https://github.com/Aarnonn/gradio.git@fix/fill-height-empty-footer-12992"
-
-RUN pip install --no-cache-dir --upgrade ${INSTALL_TARGET}
-
 COPY --chown=user . /app
 CMD ["python", "app.py"]