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/PlexInfo.tsx

@@ -4,12 +4,11 @@ import { useTranslation } from "react-i18next";
 import { useQueryClient } from "@tanstack/react-query";
 import { Check, ExternalLink, FolderPlus, ListPlus, Play, RotateCcw, Star, X } from "lucide-react";
 import { api, type PlexCard, type PlexFilters, type PlexItemDetail } from "../lib/api";
-import { formatRuntime } from "../lib/format";
+import { formatCompact, formatDecimal, formatMoney, formatRuntime } from "../lib/format";
 import { notifyActionError } from "../lib/actionErrors";
 import { DetailCustomizeMenu, Filterable, PrefToggle } from "./plexDetailUi";
 import { tmdbBackdropUrl, useCrossfadeBackdrop, useDetailPrefs } from "../lib/plexDetail";
 import { usePref } from "../lib/usePref";
-import i18n from "../i18n";
 import { Carousel } from "./ui/Carousel";
 import PlexCollectionEditor from "./PlexCollectionEditor";
 import PlexPlaylistAdd from "./PlexPlaylistAdd";
@@ -38,24 +37,6 @@ import { regionName, vocab } from "../lib/vocab";
 // The TMDB-enriched pieces (multi-source ratings row, facts, keyword chips, full crew — E5 S5) render
 // on the page variant only; the overlay stays lean.
 
-// Localize the grouping/compact notation to the active language (the app convention, lib/api/core.ts);
-// `i18n.language` is read at call time, and the component re-renders on a language switch. Currency stays
-// USD — TMDB budget/revenue figures are USD regardless of the viewer's language.
-const compact = (n: number) =>
-  new Intl.NumberFormat(i18n.language, { notation: "compact" }).format(n);
-const money = (n: number) =>
-  new Intl.NumberFormat(i18n.language, {
-    notation: "compact",
-    style: "currency",
-    currency: "USD",
-    // The minimum is load-bearing, not a default written out: given only a maximum, a compact
-    // format is free to pad to it. The very same options render "$160.0M" on Node 22 and "$160M"
-    // on Node 24 (measured 2026-09-20 — the server gate was red on exactly this while the local one
-    // was green), and browsers split along the same line. Pin it rather than inherit the engine's.
-    minimumFractionDigits: 0,
-    maximumFractionDigits: 1,
-  }).format(n);
-
 // One rating chip's number: a filter button when this is the score the backend's ratingMin column
 // tracks, plain text otherwise. It lives at MODULE level, not inside RatingsRow, because a component
 // declared during render is a NEW component type on every render — React unmounts and remounts the
@@ -70,7 +51,8 @@ function Score({
   filterable: boolean;
   onFilterRating?: (score: number) => void;
 }) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const shown = formatDecimal(score, i18n.language);
   return filterable && onFilterRating ? (
     <Pressable
       onClick={() => onFilterRating(Math.floor(score))}
@@ -78,12 +60,12 @@ function Score({
       title={t("plex.info.filterRating", { n: Math.floor(score) })}
     >
       <Star className="h-3.5 w-3.5 fill-current" />
-      {score.toFixed(1)}
+      {shown}
     </Pressable>
   ) : (
     <span className="inline-flex items-center gap-1">
       <Star className="h-3.5 w-3.5 fill-current" />
-      {score.toFixed(1)}
+      {shown}
     </span>
   );
 }
@@ -110,7 +92,7 @@ function RatingsRow({
    *  theme's dark gold would sit on the player's black (2.6:1, measured). */
   onDark?: boolean;
 }) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
   const primary = imdbRating ?? audience ?? null; // the filterable score
   // The source label is the chip's own colour at full strength: dimmed to 70% it fell under 4.5:1.
   const chipCls = `inline-flex items-center gap-1 rounded-md px-1.5 py-0.5 font-semibold ${
@@ -147,7 +129,7 @@ function RatingsRow({
         <span className={chipCls}>
           <Score score={tmdbRating} filterable={false} />
           <span className="text-2xs font-normal">
-            TMDb{has(tmdbVotes) ? ` · ${compact(tmdbVotes)}` : ""}
+            TMDb{has(tmdbVotes) ? ` · ${formatCompact(tmdbVotes, i18n.language)}` : ""}
           </span>
         </span>
       )}
@@ -171,7 +153,8 @@ function FactsPanel({
   detail: PlexItemDetail;
   onFilter?: (patch: Partial<PlexFilters>) => void;
 }) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const lang = i18n.language;
   const tmdb = detail.tmdb;
   const studios = tmdb?.studios?.length ? tmdb.studios : detail.studio ? [detail.studio] : [];
   const rows: { key: string; label: string; node: ReactNode }[] = [];
@@ -195,7 +178,7 @@ function FactsPanel({
     rows.push({
       key: "runtime",
       label: t("plex.info.facts.runtime"),
-      node: formatRuntime(detail.duration_seconds),
+      node: formatRuntime(detail.duration_seconds, lang),
     });
   const cert = detail.content_rating;
   if (cert)
@@ -209,9 +192,17 @@ function FactsPanel({
       ),
     });
   if (tmdb?.budget)
-    rows.push({ key: "budget", label: t("plex.info.facts.budget"), node: money(tmdb.budget) });
+    rows.push({
+      key: "budget",
+      label: t("plex.info.facts.budget"),
+      node: formatMoney(tmdb.budget, lang),
+    });
   if (tmdb?.revenue)
-    rows.push({ key: "revenue", label: t("plex.info.facts.revenue"), node: money(tmdb.revenue) });
+    rows.push({
+      key: "revenue",
+      label: t("plex.info.facts.revenue"),
+      node: formatMoney(tmdb.revenue, lang),
+    });
   if (studios.length)
     rows.push({
       key: "studios",
@@ -372,7 +363,8 @@ export default function PlexInfo({
   onPlayItem,
   library,
 }: Props) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const lang = i18n.language;
   const qc = useQueryClient();
 
   // Personal display prefs (default ON), shared with the series detail pages via useDetailPrefs:
@@ -601,7 +593,7 @@ export default function PlexInfo({
                   </Filterable>
                 )}
                 {detail.duration_seconds ? (
-                  <span className={mutedCls}>{formatRuntime(detail.duration_seconds)}</span>
+                  <span className={mutedCls}>{formatRuntime(detail.duration_seconds, lang)}</span>
                 ) : null}
                 {detail.studio && (
                   <Filterable