fix(i18n): numbers, units, dates and order in the UI language, and after a switch (E30 S3)

Every locale formatter takes the language as an argument. Under the React
Compiler a formatter that read the i18n singleton was memoized on its other
arguments, so a card kept "2 hr 4 min" after a switch to Hungarian; plexLang()
had the same flaw and left Plex queries in the old language. Components now
take the language from useTranslation, and the signature makes forgetting it
a type error.

- ratings, file sizes, stream stats: the language's decimal mark ("8,3")
- view and subscriber counts compact in the language ("1,2 E")
- seconds as the language's unit ("6 mp") in the sliders and the stats
- a person's birth and death dates as dates, not ISO strings
- A-Z lists by the shown name in the language's alphabet (compareText),
  the tag catalog re-sorted by its translated names
- lint local/locale-format (was date-format) also refuses Intl.NumberFormat
  outside lib/format.ts, localeCompare, and a component reading the language
  off the i18n singleton

frontend/src/components/BootGate.tsx

@@ -104,6 +104,7 @@ export default function BootGate({ children }: { children: ReactNode }) {
     const account = meRef.current;
     if (account && getActiveAccount() !== account.id) setActiveAccount(account.id);
     const lang = account?.preferences?.language;
+    // eslint-disable-next-line local/locale-format -- a one-shot read in an effect, compared before adopting the account's language; nothing renders it, so there is no memoized value to go stale.
     if (typeof lang === "string" && isSupported(lang) && lang !== i18n.language) setLanguage(lang);
     // eslint-disable-next-line react-hooks/set-state-in-effect -- the adoption latch. It cannot be derived: the whole point is that the tree mounts only AFTER the pin and the language have been applied, and both are writes to things outside React (sessionStorage, i18n). A layout effect so the frame that first shows the app already has them.
     setReadyFor(identity);