Module sync 

Background sync service for auto-pulling trees from Nostr

Subscribes to:

1. Own trees (all visibility levels) - highest priority
2. Followed users’ public trees - lower priority

Uses WebRTC peers first, falls back to Blossom HTTP servers

Structs

BackgroundSync

Background sync service

SyncConfig

Configuration for background sync

SyncStatus

Overall sync status

SyncTask

A tree to sync

Enums

SyncPriority

Sync priority levels