update dockerfile

Dockerfile

@@ -1,12 +1,28 @@
+# Production stage - MCP Backend Only
 FROM node:18-slim
 
+# Create non-root user for security
+RUN addgroup --system --gid 1001 nodejs && \
+    adduser --system --uid 1001 --gid 1001 nodejs
+
 WORKDIR /app
 
+# Copy package files
 COPY package*.json ./
-RUN npm install
 
-COPY . .
+# Install only production dependencies
+RUN npm ci --only=production && npm cache clean --force
 
-EXPOSE 3000
+# Copy source code (only backend files needed)
+COPY src ./src
 
+# Set environment variables
+ENV NODE_ENV=production
+ENV EXPRESS_SERVER_URL=http://localhost:3000
+ENV ENABLE_CANVAS_SYNC=true
+
+# Switch to non-root user
+USER nodejs
+
+# Run MCP server only
 CMD ["npm", "start"]