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/Playlists.tsx

@@ -160,7 +160,8 @@ export default function Playlists() {
   // The selected playlist lives in PlaylistsProvider, shared with the PlaylistsRail (which owns the
   // list + its rail controls). This detail pane reacts to the selection.
   const { selectedId } = usePlaylists();
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const lang = i18n.language;
   const qc = useQueryClient();
   const plActions = usePlaylistActions();
   const [renaming, setRenaming] = useState(false);
@@ -391,8 +392,8 @@ export default function Playlists() {
 
   const filterActive = Object.values(filters).some(isActive);
   const shown = useMemo(
-    () => applyView(filterRows(items, columns, filters), columns, viewSort, groupBy),
-    [items, columns, filters, viewSort, groupBy],
+    () => applyView(filterRows(items, columns, filters), columns, viewSort, groupBy, lang),
+    [items, columns, filters, viewSort, groupBy, lang],
   );
   // Read by the drag announcements, which must report the CURRENT positions without making the
   // announcement closures a render dependency of DndContext.
@@ -909,7 +910,7 @@ export default function Playlists() {
                 <div className="flex items-center gap-2 mt-1 flex-wrap">
                   <span className="text-xs text-muted">
                     {t("playlists.itemCount", { count: items.length })}
-                    {totalSeconds > 0 && ` · ${formatRuntime(totalSeconds)}`}
+                    {totalSeconds > 0 && ` · ${formatRuntime(totalSeconds, lang)}`}
                     {filterActive && ` · ${t("playlists.filteredCount", { count: shown.length })}`}
                   </span>
                   {(items.length > 1 || viewActive) && (