Last post-state per currency wins; non-currency grants collapse to final
count per (type, id). Deltas are verbatim queued, no cascade. SaveChanges
+ DB tx commit happen atomically inside Commit; failure leaves rollback
to DisposeAsync. CS0649 warning on _committed is now resolved.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>