Add production Docker setup

- Dockerfile: multi-stage build (deps → builder → standalone runner)
- docker-compose.prod.yml: app on port 3010 + PostgreSQL 16
- entrypoint.sh: runs prisma migrate deploy then starts node server
- next.config.ts: standalone output for minimal Docker image
- .dockerignore: exclude dev files from build context

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

entrypoint.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+set -e
+
+echo "Running database migrations..."
+npx prisma migrate deploy
+
+echo "Starting Next.js..."
+exec node server.js