Update Dockerfile for python

Dockerfile

@@ -10,6 +10,12 @@ RUN npm run build
 FROM node:18-alpine
 WORKDIR /app/backend
 
+# Install python and build dependencies
+RUN apk add --no-cache python3 py3-pip python3-dev build-base && \
+    python3 -m venv /opt/venv
+
+ENV PATH="/opt/venv/bin:$PATH"
+
 # Install backend dependencies
 COPY backend/package*.json ./
 RUN npm install --production
@@ -17,6 +23,9 @@ RUN npm install --production
 # Copy backend source
 COPY backend/ ./
 
+# Install python dependencies
+RUN pip install --no-cache-dir -r python_service/requirements.txt
+
 # Copy built frontend to the public directory expected by server.js
 # (__dirname is /app/backend/src, so ../../public is /app/public)
 COPY --from=frontend-build /app/frontend/dist /app/public