feat(storage): Add Nextcloud FPM + MinIO + Filestash stack (closes #385)

[D2758695161]

Summary

This PR implements the Storage Stack bounty task (illbnm#385) with:

Components

• Nextcloud FPM with separate nginx web server (not Apache-based)
• MinIO for S3-compatible object storage with both console and S3 API endpoints
• Filestash as a web file browser for MinIO
• PostgreSQL database for Nextcloud
• Redis for Nextcloud caching

Features

• Full Traefik labels for reverse proxy configuration
• Separate PHP-FPM and nginx containers for better performance
• S3 primary storage backend configuration for Nextcloud
• Health checks on all containers
• Complete .env.example template with all required credentials

Routes

• Nextcloud: nextcloud.${DOMAIN}
• MinIO Console: minio-console.${DOMAIN}
• MinIO S3 API: s3.${DOMAIN}
• Filestash: files.${DOMAIN}

Payment

Payment address: 0xaae0101ac77a2e4e0ea826eb4d309374f029b0a6

---

Bounty illbnm#385

[D2758695161]

Payment Information

Payment address: 0xaae0101ac77a2e4e0ea826eb4d309374f029b0a6

Please send bounty payment to this address upon merge.