fix: use standard Next.js build

Dockerfile

@@ -14,11 +14,10 @@ WORKDIR /app
 
 ENV NODE_ENV=production
 
-# Copy only production dependencies and built files
-COPY --from=builder /app/.next/standalone ./
-COPY --from=builder /app/.next/static ./.next/static
-COPY --from=builder /app/public ./public 2>/dev/null || true
+COPY --from=builder /app/.next ./.next
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./package.json
 
 EXPOSE 3000
 
-CMD ["node", "server.js"]
+CMD ["npm", "start"]