fix: the follow-ups the v4.2.1 audit turned up

Five findings from auditing the release branch, none of them a blocker for it,
all of them things it would have shipped with.

The mirrored booking price only survived an edit when the form happened to fill
metadata of its own. Both reservation forms and the phone sheet sent
`metadata: null` whenever the form had no metadata key to send, and null clears
the column outright — so restaurant, event, tour, parking, other, a hotel with
no check-in times and a transport with no carrier details all lost the price
again on the next save. They send the object now: it still clears what the form
dropped, and the server carries the price across (#2233).

Your share counted expenses nobody has paid for, while the balances right below
it stopped counting them. The tile contradicted the panel it sits in (#2225).

App.tsx kept its own list of routes that must not mount authed-only widgets, and
it had already drifted from the one the response interceptor uses: this one
named /public/journey/, that one covers all of /public/. It reads
isAuthPublicPath now, so a route cannot be public to one and not the other.

LLM_TIMEOUT_MS and TREK_PLUGINS_IGNORE_TREK_RANGE shipped in .env.example but
not in the compose file most installs actually read.

And a typo in the Russian offline copy: Завершёна → Завершена.

shared/src/i18n/ru/settings.ts

@@ -496,7 +496,7 @@ const settings: TranslationStrings = {
   'settings.offline.storage.tripsTitle': 'Поездки',
   'settings.offline.storage.tripOn': 'Хранится офлайн',
   'settings.offline.storage.tripOff': 'Не хранится',
-  'settings.offline.storage.tripFinished': 'Завершёна. Сохраняется, только если вы её включите.',
+  'settings.offline.storage.tripFinished': 'Завершена. Сохраняется, только если вы её включите.',
   'settings.offline.notice.stored': 'На этом устройстве сохранено поездок: {count}',
   'settings.offline.notice.nothing': 'Сохранять нечего. Включите поездки, которые хотите оставить.',
   'settings.offline.notice.busy': 'Синхронизация уже идёт. Повторите попытку через мгновение.',