feat: Add 15 backend service stub files with TODO implementations
Stub files for all services declared in services/mod.rs:
- Panel adapters: AMP, Pterodactyl, Companion (NATS-based)
- Wipe pipeline: WipeEngine, Scheduler, HealthChecker, BackupManager
- Infrastructure: NatsBridge (JetStream), SteamUpdateWatcher, MapManager
- Notifications: Discord webhooks, Pushbullet push notifications
- Platform: LicenseService, CloudflareService, encryption utilities
Each file has struct definitions, method signatures with proper types,
and descriptive TODO comments outlining the implementation plan.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
cc8c1e3519