Offline-First Sync Engine: Outbox Queue & Optimistic Rollback

Mobile offline-first architecture rests on one core mechanic: every local edit is applied immediately and also appended to a persistent outbox queue, so the app keeps working with zero network at all. This simulator renders a 5×5 grid of local data records plus a device and server node in 3D — toggle the connection off and watch the outbox queue back up as you (or the automatic edit-rate slider) keep mutating records, then toggle back online and watch queued mutations fly to the server one at a time, either committing (green) or getting rejected and rolled back (a red flash) according to the conflict-rate you set. Live readouts track queue depth, in-flight packets, total synced mutations, rollbacks, and accumulated offline time.