fix(ui): a page's sub-tab is remembered per browser tab, not forever

Settings, Configuration, Statistics and Users kept the last sub-tab in localStorage, so every
fresh tab opened Configuration on "Plex" as if that were its home. useTabPersistedState keeps it
in sessionStorage (account-scoped): a reload and a trip to another page keep it, a new tab starts
on the first sub-tab. The pre-selects (a Review link, the Google-link return) write the same store;
a value an older build left in localStorage is cleared on first read.

frontend/src/components/Stats.tsx

@@ -8,7 +8,7 @@ import { formatEta, formatNumber, formatUnit, quotaActionLabel } from "../lib/fo
 import { notify } from "../lib/notifications";
 import { notifyYouTubeActionError } from "../lib/youtubeErrors";
 import { useWizard } from "./wizardContext";
-import { LS, useAccountPersistedState } from "../lib/storage";
+import { LS, useTabPersistedState } from "../lib/storage";
 import Tooltip from "./ui/Tooltip";
 import { LoadingState, StateMessage } from "./ui/QueryState";
 import FilterChipGroup from "./ui/FilterChipGroup";
@@ -34,7 +34,7 @@ export default function Stats() {
   const me = useMe();
   const { t } = useTranslation();
   const isAdmin = me.role === "admin";
-  const [tabRaw, setTab] = useAccountPersistedState(LS.statsTab, "overview");
+  const [tabRaw, setTab] = useTabPersistedState(LS.statsTab, "overview");
   // Clamp at render: only admins may land on the System tab (covers a stale stored value).
   const tab: StatsTab = tabRaw === "system" && isAdmin ? "system" : "overview";
   const panel = useTabPanel();