Add production Docker deployment configuration

- Add multi-stage Dockerfile for Next.js standalone build
- Add docker-compose.deploy.yml for production deployment
- Add entrypoint.sh for database migration and startup
- Add .dockerignore for efficient Docker builds
- Add docker/.env.production with all required env vars
- Add Caddyfile.prod with security headers and optimizations
- Update next.config.ts with output: standalone for Docker
- Add DOCKER_DEPLOYMENT.md with comprehensive deployment guide

docker/Caddyfile.prod

@@ -0,0 +1,22 @@
+{$DOMAIN} {
+  reverse_proxy web:3000 {
+    header_up Host {host}
+    header_up X-Real-IP {remote_host}
+    header_up X-Forwarded-For {remote_host}
+    header_up X-Forwarded-Proto {scheme}
+  }
+
+  # Compression
+  encode gzip
+
+  # Security headers
+  header X-Content-Type-Options nosniff
+  header X-Frame-Options SAMEORIGIN
+  header X-XSS-Protection "1; mode=block"
+  header Referrer-Policy strict-origin-when-cross-origin
+}
+
+# MinIO console (optional - remove in production for security)
+# minio.{$DOMAIN} {
+#   reverse_proxy minio:9001
+# }