feat(docker): production-ready Dockerfile + Portainer compose stack

- Rewrite Dockerfile: multi-stage pnpm monorepo build with Next.js
  standalone output, non-root user, minimal runner image
- Enable next.config.ts `output: standalone` + serverExternalPackages
- Rewrite docker/compose.prod.yml: full production stack with migrate
  service, minio-init, named networks, build context for Portainer
- Add scripts/migrate.mjs: standalone Drizzle migration runner
- Update .dockerignore for cleaner build context

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

apps/web/next.config.ts

@@ -42,7 +42,8 @@ const securityHeaders = [
 ];
 
 const nextConfig: NextConfig = {
-  output: 'standalone',
+  output: "standalone",
+  serverExternalPackages: ["@epicure/db", "pg", "drizzle-orm"],
   async headers() {
     return [
       {