- Created manifest.go with proper Manifest structure including blob sizes
- Updated manifest generation to include compressed size for each blob
- Added TotalCompressedSize field to manifest for quick access
- Renamed backup package to snapshot for clarity
- Updated snapshot list to show all remote snapshots
- Remote snapshots not in local DB fetch manifest to get size
- Local snapshots not in remote are automatically deleted
- Removed backwards compatibility code (pre-1.0, no users)
- Fixed prune command to use new manifest format
- Updated all imports and references from backup to snapshot
