Completes the two-way watch-state sync with two scheduler jobs:
- plex_watch_sync (default 30m): pull recent Plex-side changes (watch history + on-deck, filtered
to the owner account) into Siftlode under last-write-wins (_pull_apply + a _same_state ping-pong
guard + skew tolerance), then re-push any still-unsynced local states.
- plex_watch_reconcile (default daily): full section rescan; uses synced_to_plex to settle what the
incremental feed can't — notably propagating a Plex-side un-watch (clear a previously-mirrored row
Plex no longer has) — while re-pushing never-synced local states and never touching hidden
(Siftlode-only) rows. Union-preserving.
PlexClient gains accounts/watch_history/on_deck; _scan_plex_states is factored out and shared with
the one-time import. Owner accountID is resolved once and cached on the link. Both jobs are
registered in the scheduler (pause-skip, activity tracking, run-now, admin-tunable intervals) with
trilingual (HU/EN/DE) labels + descriptions. New config default plex_watch_reconcile_interval_min.
Verified live against the real Plex server: read feeds, last-write-wins, dirty re-push, the
incremental job end-to-end, and a full reconcile that cleared exactly the one un-watched item with
zero collateral across 17976 scanned.