Completes offline Phase 1 (frontend). Generalises the POS-orders-only queue into
a reusable write engine and fixes the two correctness bugs in the old path.
- offline-db: generic `outbox` store (DB v3, order_queue/kv preserved) with
enqueue/list/update/remove + a persisted client→server id map.
- outbox.ts: drains in causal order — remaps local_* ids to server ids (blocking
an op until its creator syncs), sends each op with its idempotency key, and
classifies failures (offline → stop; 5xx / in-progress → retry; 4xx → poison
after 5 attempts). remap/blocked logic validated against representative cases.
- client: apiPost/Put/Patch/Delete take an optional idempotencyKey →
`Idempotency-Key` header; ApiClientError now carries HTTP status.
- submit-order: generates ONE idempotency key per submit, used for both the
online attempt and the queued replay → server de-dups (no more double-create);
offline create carries createsClientId so a later add-items remaps onto the
real order instead of spawning a second order.
- use-offline-sync: drains the outbox, one-time migrates legacy order_queue
items, invalidates queries after a successful sync.
tsc + production build clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
First slice of offline-first (Phase 1). Makes every dashboard area *viewable*
offline with last-synced data, instead of empty lists on an offline reload
(previously only next-pwa's 10-min API cache survived).
- offline-db: add a generic `kv` IndexedDB store (DB v2, preserves order_queue)
with kvGet/kvSet/kvDelete; all degrade silently on quota/unavailable.
- query-persister: debounced snapshot of the React Query cache via
dehydrate/hydrate (no new dependency). Restore is guarded by a schema buster,
24h max-age, and a café scope so one tenant never hydrates another's data.
- providers: gcTime 24h so hydrated data isn't GC'd; restore on mount + persist
on cache changes, re-scoped when the signed-in café changes.
No write-path changes; the existing POS order queue is untouched. Next in
Phase 1: generalize that queue into an idempotent outbox with client→server
ID remapping.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
soroush.asadi