Make the stored application timezone authoritative everywhere
The kids' Quest Log again renders each instance's overdue state from the API snapshot's `overdue` flag, which the API computes in the stored application timezone. The browser-local overdue check from task fd1093b5 (`_isOverdue` against `_now`) is removed; `_now` only drives the header clock and date. The admin settings route (PATCH /api/v1/admin/settings), the only settings writer, now holds the missed-sweep scheduler's settings_lock across the write and calls settings_changed, so saving `timezone` or `day_rollover_time` re-plans a sleeping scheduler (review finding TZ-001). An app without a scheduler just writes. Tests: the card shows the snapshot's overdue state whatever the browser's zone or clock says; an admin PATCH of the zone or the rollover re-plans a sleeping scheduler; one saved zone (Asia/Kolkata) is read identically by the panel snapshot, the admin snapshot and the scheduler delay. Task: 7e173881-fb99-426f-a2f0-2678439ffc39 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in: