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/lib/adminUsersTab.ts

@@ -1,8 +1,8 @@
-import { LS, setAccountRaw } from "./storage";
+import { LS, setTabRaw } from "./storage";
 
 // The admin Users page's persisted-tab key + the Access-requests tab id, plus a helper to
 // pre-select that tab before navigating there (a notification's "Review" link uses it —
-// useAccountPersistedState reads the key on mount, and the page mounts fresh on navigation).
+// useTabPersistedState reads the key on mount, and the page mounts fresh on navigation).
 //
 // Kept out of AdminUsers.tsx so callers (App, NotificationsPanel) can pre-select the tab
 // WITHOUT statically importing the — now lazy-loaded — admin page, which would otherwise pull
@@ -11,5 +11,5 @@ export const ADMIN_USERS_TAB_KEY = LS.adminUsersTab;
 const ADMIN_USERS_ACCESS_TAB = "access";
 
 export function focusAccessRequestsTab(): void {
-  setAccountRaw(ADMIN_USERS_TAB_KEY, ADMIN_USERS_ACCESS_TAB);
+  setTabRaw(ADMIN_USERS_TAB_KEY, ADMIN_USERS_ACCESS_TAB);
 }