Fix Dockerfile: simplify build steps

Dockerfile

@@ -2,22 +2,11 @@ FROM node:20-alpine
 
 WORKDIR /app
 
-# Copy package files first for better cache
 COPY package*.json ./
-
-# Install all deps including dev for build
 RUN npm ci
-
-# Copy source
 COPY . .
-
-# Build the Vite app
 RUN npm run build
-
-# Install production server deps
-RUN npm install --omit=dev express http-proxy-middleware
+RUN npm prune --production
 
 EXPOSE 7860
-
-# Start the proxy server (serves static + proxies /api/anthropic)
 CMD ["node", "server.mjs"]