feat(backup): Add Rclone, .env.example, and backup-to-cloud.sh

[D2758695161]

Summary

Enhances the Backup & DR Stack for homelab-stack as requested in Issue illbnm#372.

Enhancements:

• Rclone Service - Added Docker container for cloud backup sync with REST API
• Backup .env.example - Added comprehensive environment variables template
• Rclone Config Template - Added config/rclone/rclone.conf.example with S3, Google Drive, B2, OneDrive, Mega, SFTP examples
• backup-to-cloud.sh Script - Added script for syncing backups to cloud storage via rclone

Existing Services (preserved):

• Duplicati - Backup client with web UI
• Restic REST Server - S3-compatible backup repository

Files Added:

• stacks/backup/.env.example - Environment variables for backup stack
• config/rclone/rclone.conf.example - Rclone configuration template
• scripts/backup-to-cloud.sh - Cloud backup sync script

Files Changed:

• stacks/backup/docker-compose.yml - Added Rclone service with Traefik labels

Features:

• Rclone REST API exposed via Traefik for remote management
• Supports multiple cloud providers (S3, Google Drive, B2, OneDrive, Mega, SFTP)
• backup-to-cloud.sh supports dry-run, verbose mode, and specific remote selection
• Health checks configured for all containers

Payment:

• Bounty:
• Address: �xaae0101ac77a2e4e0ea826eb4d309374f029b0a6

Closes illbnm#372