Backend (docs/UI_UX_PLAN.md B-1, B-2):
- Request::SetSyncPaused { paused, until } pauses the drain worker and the
mirror reconcile. FUSE reads, write staging, the watcher and the poll keep
running. The pause is persisted in the `state` table (`sync_paused_until`),
so it survives a restart; a timed pause ends by itself through a timer
thread, re-armed on mount. Resuming wakes the drain and runs a full
reconcile. Response::Status gains `paused` and `paused_until`.
- Request::ListPendingOps lists the queue with paths, attempts, last error,
next attempt and parked/failing flags. Request::RetryPendingOp { id } makes
one backed-off op (or every failed one) due now. Parked ops are never
un-parked and nothing is dropped from the queue.
Front ends:
- Sync page: a status card with Pause/Resume (split button with 1 h, 8 h and
24 h pauses) and a "Waiting to Upload" list with Retry now and Retry All.
- The sidebar strip and the tray show the paused state; the tray gains Pause
Sync / Resume Sync and names failing changes.
- CLI: `pdfs sync pause [--for 30m|1h|2d]`, `pdfs sync resume`,
`pdfs sync queue`, `pdfs sync retry [id]`; `pdfs status` reports a pause.
Not in this phase: merging Activity into the Sync page, discarding a queued
op (needs a recovery copy first), and per-folder pause.
nvrl