The `{Y-m-d:H-M}` segment of an Xtream timeshift URL is read by the panel
with `strtotime()` in ITS timezone (`server_info.timezone`), never the
viewer's. The timezone was learned in memory only, by the store's
`checkPortalStatus()`, so the Favorites / Recent catch-up resolver — which
reads the STORED playlist row — always fell back to the viewer's local
clock and asked the panel for the wrong programme (#1562).
- Normalize the panel's clock once (`resolveXtreamServerTimezone`): an
ICU-resolvable name is kept, otherwise a `UTC±HH:MM` offset is derived
from the `time_now` / `timestamp_now` clock pair, so spellings such as
`UTC+3` no longer silently mean "local time".
- Persist it on the playlist row through `transformPlaylistMeta` (no-op
when unchanged) and project it back from the payload in
`DB_GET_PLAYLIST`, so both catch-up entry points and a restart see it.
- Format with `hourCycle: 'h23'` (server midnight is `00`, never `24`) and
read timestamp-less EPG `start`/`end` strings in the panel's clock.
- Mock: `tzoffset:tzoffset` scenario with an unusable timezone name and a
+03:00 clock pair; Electron e2e covers Live TV, Favorites, a restart into
Global favorites, and the clock-pair derivation at a UTC-3 viewer.
Closes#1562
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>