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>

.dockerignore

@@ -0,0 +1,14 @@
+.git
+.gitignore
+.env
+.env.local
+.env.production
+node_modules
+.next
+src/generated
+prisma/migrations
+*.md
+docker-compose.yml
+docker-compose.prod.yml
+Dockerfile
+.dockerignore