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/channelCells.tsx

@@ -12,7 +12,8 @@ import { isFullySynced } from "./channelSync";
 // full history are both in — folding the retired Sync column's at-a-glance status into the value it
 // describes. Full detail stays in the hover tooltip.
 export function StoredCell({ c }: { c: ManagedChannel }) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const lang = i18n.language;
   return (
     <span className="inline-flex items-center justify-end gap-1 text-muted tabular-nums">
       {isFullySynced(c) && (
@@ -24,7 +25,7 @@ export function StoredCell({ c }: { c: ManagedChannel }) {
           />
         </Tooltip>
       )}
-      {formatNumber(c.stored_videos)}
+      {formatNumber(c.stored_videos, lang)}
     </span>
   );
 }