TZ-002: with no zone stored the API reads its clock in the host's local
time, but the panel fell back to Home Assistant's zone and the admin app
to the browser's, so dates could disagree near midnight. The API now
names the zone it actually uses (api/host_zone.py: the stored zone, else
the host's own IANA zone from TZ, /etc/localtime or /etc/timezone) and
publishes it as the panel snapshot's `timezone` and the admin settings'
read-only `effective_timezone`. Both cards and the admin app format in
that one zone; Home Assistant's or the browser's zone applies only when
none is published.
TZ-003: snapshot_from_api_payload reads `timezone` with a "" default, so
an integration upgraded ahead of its API keeps refreshing against the
pre-change payload.
Task 7e173881-fb99-426f-a2f0-2678439ffc39
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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>