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/Feed.tsx

@@ -136,7 +136,8 @@ export default function Feed({
   // that are constant within one channel (subscribers, priority) — they'd be meaningless.
   channelScoped?: boolean;
 }) {
-  const { t } = useTranslation();
+  const { t, i18n: ui } = useTranslation();
+  const lang = ui.language;
   // "Connect YouTube" onboarding lives in WizardProvider (the empty-state CTA when not connected).
   const { openWizard: onOpenWizard } = useWizard();
   // Same list the panel's badge counts — see lib/useActiveFilters.
@@ -439,6 +440,7 @@ export default function Feed({
       withOverrides(ytLoaded),
       ytSort.key as SortKey,
       ytSort.dir,
+      lang,
     );
     const ytPlayerQueue: Video[] = ytItems.filter((v) => v.status !== "hidden");
     const ytError =