Add full CRUD support for managing collections on Android, accessible
via Settings > Vault > Collections. Collections are organization-scoped
vault items available on paid plans.
Changes include:
- Network layer: CollectionsApi, CollectionService, request/response models
- Data layer: CollectionManager with encrypt > API > disk > decrypt flow
- Permission model: expanded SyncResponseJson.Permissions and Organization
with collection-specific permission fields
- UI: CollectionsScreen (list with org subtitles, permission-gated FAB),
CollectionAddEditScreen (name field, save, delete with confirmation)
- Navigation: type-safe routes wired through VaultSettings entry point
- VaultDiskSource.deleteCollection and VaultSdkSource.encryptCollection stub
Note: encryptCollection is stubbed pending SDK release (SDK changes are
implemented but not yet published). Create/update will fail at runtime
until the SDK is updated.
