GalleryViewModel.load() now has a three-tier resolution for manifest entries:
1. statusService.lastManifest — in-memory, freshest
2. NASManifestCache disk cache — survives restarts
3. Direct NAS download — fallback when both caches are cold (first launch after install,
or before BackupStatusService reconcile has completed)
The direct download also populates NASManifestCache so subsequent opens are instant.
Also adds GalleryViewModel.bind(to:connection:) which subscribes to
statusService.$lastManifest and automatically reloads gallery items when
BackupStatusService finishes reconciling — gallery updates without manual pull-to-refresh.
Co-Authored-By: Kutesir <kutesir@provoc.ug>
Co-Authored-By: Sentry <sentry@provoc.ug>