Offline writes now queue + apply optimistically instead of throwing.
On reconnect, the queue drains automatically; conflicts and rejections
surface as one-time SnackBars so the user knows their edit didn't land.
- Drift schema v3: `pending_writes` table (verb + payload + baseline +
tries + last_error). Negative ids serve as cache placeholders for
offline-created rows until replay assigns the server id.
- Each write repository (notes, tasks, projects, milestones, events)
now catches NetworkException, applies the change to cache (with a
fresh `nextTempId()` for creates), and enqueues the API call.
- Edits to a still-queued offline-created row coalesce into the
original create payload — only one server call per row, in order.
- Deletes of still-queued offline-created rows drop the queue entry
and the cache row; no server call ever happens.
- New WriteQueue service drains the queue oldest-first.
Server-wins on `updated_at` baseline check (notes/tasks/projects);
last-writer-wins for milestones/events (no getOne available).
4xx → drop + surface as `rejected`; conflict → drop + `overwritten`;
404 on update → drop + `missing`; 5xx/network → keep + retry next
online cycle.
- Replay fires on AuthStatus → authenticated transitions
(cold-start, came-back-online, login).
- OfflineBanner shows "Retry (N)" with the pending-writes count.
- Distinct ServerException added so 4xx no longer masquerade as
NetworkException — the queue can drop them instead of looping.
flutter analyze clean; 21 tests pass (3 new for QueueFailure messaging).
Phase 4 (read-only UI indicators on cached/temp rows) still ahead.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
bvandeusen