Flutter Outbox Pattern

Persistent, idempotent retries for writes that absolutely must reach the server. An Outbox is a durable queue, stored on the device, that holds the intent of a server-bound write. The user's action is recorded to the outbox first — synchronously, before the network call. A dispatcher then drains the queue: every time the app starts, every time connectivity is restored, every time the user resumes the app, and once eagerly right after the action is enqueued. If the request succeeds, the entry is