refactor: optimize Docker deployment with standalone mode

- Enable Next.js standalone output for smaller image size
- Remove unnecessary npm install in production stage
- Use direct node execution instead of npm start
- Add .dockerignore to exclude unnecessary files from build context

.dockerignore

@@ -0,0 +1,10 @@
+node_modules
+.next
+.git
+.gitignore
+.claude
+*.md
+.env*.local
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

Dockerfile

@@ -13,8 +13,7 @@ WORKDIR /app
 
 ENV NODE_ENV=production
 
-RUN npm install next --save
-
+# Copy standalone output
 COPY --from=builder /app/.next/standalone ./
 COPY --from=builder /app/.next/static ./.next/static
 COPY --from=builder /app/public ./public
@@ -24,4 +23,4 @@ EXPOSE 3000
 ENV PORT=3000
 ENV HOSTNAME="0.0.0.0"
 
-CMD ["npm", "start"]
+CMD ["node", "server.js"]

next.config.mjs

@@ -1,3 +1,5 @@
 /** @type {import('next').NextConfig} */
-const nextConfig = {};
+const nextConfig = {
+  output: 'standalone',
+};
 export default nextConfig;