feat(users): show last-access timestamp per user

Maps Navidrome's lastAccessAt onto NdUser and renders it in the
User Management row as a localized relative time (Intl.RelativeTimeFormat
with the current i18n language). Tooltip carries the absolute
timestamp. Navidrome returns 0001-01-01 for never-accessed users —
detected and shown as the localized "Never" label.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/api/navidromeAdmin.ts

@@ -13,6 +13,7 @@ export interface NdUser {
   isAdmin: boolean;
   libraryIds: number[];
   lastLoginAt?: string | null;
+  lastAccessAt?: string | null;
   createdAt?: string;
   updatedAt?: string;
 }
@@ -56,6 +57,7 @@ export async function ndListUsers(serverUrl: string, token: string): Promise<NdU
       isAdmin: !!o.isAdmin,
       libraryIds: extractLibraryIds(o),
       lastLoginAt: (o.lastLoginAt as string | null | undefined) ?? null,
+      lastAccessAt: (o.lastAccessAt as string | null | undefined) ?? null,
       createdAt: o.createdAt as string | undefined,
       updatedAt: o.updatedAt as string | undefined,
     };

src/locales/de.ts

@@ -489,6 +489,7 @@ export const deTranslation = {
     userMgmtLibrariesValidation: 'Mindestens eine Bibliothek auswählen.',
     userMgmtLibrariesUpdateError: 'Benutzer gespeichert, aber Bibliothekszuweisung fehlgeschlagen',
     userMgmtNoLibraries: 'Keine Bibliotheken zugewiesen',
+    userMgmtNeverSeen: 'Nie',
     userMgmtSave: 'Speichern',
     userMgmtCancel: 'Abbrechen',
     userMgmtDelete: 'Löschen',

src/locales/en.ts

@@ -491,6 +491,7 @@ export const enTranslation = {
     userMgmtLibrariesValidation: 'Select at least one library.',
     userMgmtLibrariesUpdateError: 'User saved, but library assignment failed',
     userMgmtNoLibraries: 'No libraries assigned',
+    userMgmtNeverSeen: 'Never',
     userMgmtSave: 'Save',
     userMgmtCancel: 'Cancel',
     userMgmtDelete: 'Delete',

src/locales/es.ts

@@ -482,6 +482,7 @@ export const esTranslation = {
     userMgmtLibrariesValidation: 'Selecciona al menos una biblioteca.',
     userMgmtLibrariesUpdateError: 'Usuario guardado, pero la asignación de bibliotecas falló',
     userMgmtNoLibraries: 'Sin bibliotecas asignadas',
+    userMgmtNeverSeen: 'Nunca',
     userMgmtSave: 'Guardar',
     userMgmtCancel: 'Cancelar',
     userMgmtDelete: 'Eliminar',

src/locales/fr.ts

@@ -479,6 +479,7 @@ export const frTranslation = {
     userMgmtLibrariesValidation: 'Sélectionnez au moins une bibliothèque.',
     userMgmtLibrariesUpdateError: 'Utilisateur enregistré, mais l\u2019attribution des bibliothèques a échoué',
     userMgmtNoLibraries: 'Aucune bibliothèque attribuée',
+    userMgmtNeverSeen: 'Jamais',
     userMgmtSave: 'Enregistrer',
     userMgmtCancel: 'Annuler',
     userMgmtDelete: 'Supprimer',

src/locales/nb.ts

@@ -479,6 +479,7 @@ export const nbTranslation = {
     userMgmtLibrariesValidation: 'Velg minst ett bibliotek.',
     userMgmtLibrariesUpdateError: 'Brukeren ble lagret, men bibliotekstilordning mislyktes',
     userMgmtNoLibraries: 'Ingen biblioteker tilordnet',
+    userMgmtNeverSeen: 'Aldri',
     userMgmtSave: 'Lagre',
     userMgmtCancel: 'Avbryt',
     userMgmtDelete: 'Slett',

src/locales/nl.ts

@@ -478,6 +478,7 @@ export const nlTranslation = {
     userMgmtLibrariesValidation: 'Selecteer ten minste één bibliotheek.',
     userMgmtLibrariesUpdateError: 'Gebruiker opgeslagen, maar bibliotheektoewijzing mislukt',
     userMgmtNoLibraries: 'Geen bibliotheken toegewezen',
+    userMgmtNeverSeen: 'Nooit',
     userMgmtSave: 'Opslaan',
     userMgmtCancel: 'Annuleren',
     userMgmtDelete: 'Verwijderen',

src/locales/ru.ts

@@ -496,6 +496,7 @@ export const ruTranslation = {
     userMgmtLibrariesValidation: 'Выберите хотя бы одну библиотеку.',
     userMgmtLibrariesUpdateError: 'Пользователь сохранён, но не удалось назначить библиотеки',
     userMgmtNoLibraries: 'Библиотеки не назначены',
+    userMgmtNeverSeen: 'Никогда',
     userMgmtSave: 'Сохранить',
     userMgmtCancel: 'Отмена',
     userMgmtDelete: 'Удалить',

src/locales/zh.ts

@@ -474,6 +474,7 @@ export const zhTranslation = {
     userMgmtLibrariesValidation: '请至少选择一个音乐库。',
     userMgmtLibrariesUpdateError: '用户已保存，但音乐库分配失败',
     userMgmtNoLibraries: '未分配音乐库',
+    userMgmtNeverSeen: '从未',
     userMgmtSave: '保存',
     userMgmtCancel: '取消',
     userMgmtDelete: '删除',

src/pages/Settings.tsx

@@ -444,6 +444,23 @@ function UserForm({
   );
 }
 
+function formatLastSeen(iso: string | null | undefined, locale: string, neverLabel: string): string {
+  if (!iso) return neverLabel;
+  const t = new Date(iso).getTime();
+  // Navidrome returns "0001-01-01T00:00:00Z" for never-accessed users → guard against bogus epochs.
+  if (!Number.isFinite(t) || t < 1_000_000_000_000) return neverLabel;
+  const diffSec = (t - Date.now()) / 1000;
+  const abs = Math.abs(diffSec);
+  const rtf = new Intl.RelativeTimeFormat(locale, { numeric: 'auto' });
+  if (abs < 60) return rtf.format(Math.round(diffSec), 'second');
+  if (abs < 3600) return rtf.format(Math.round(diffSec / 60), 'minute');
+  if (abs < 86400) return rtf.format(Math.round(diffSec / 3600), 'hour');
+  if (abs < 604800) return rtf.format(Math.round(diffSec / 86400), 'day');
+  if (abs < 2592000) return rtf.format(Math.round(diffSec / 604800), 'week');
+  if (abs < 31536000) return rtf.format(Math.round(diffSec / 2592000), 'month');
+  return rtf.format(Math.round(diffSec / 31536000), 'year');
+}
+
 function UserManagementSection({
   serverUrl,
   token,
@@ -453,7 +470,7 @@ function UserManagementSection({
   token: string;
   currentUsername: string;
 }) {
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
   const [users, setUsers] = useState<NdUser[]>([]);
   const [libraries, setLibraries] = useState<NdLibrary[]>([]);
   const [loading, setLoading] = useState(true);
@@ -607,6 +624,10 @@ function UserManagementSection({
                   : u.libraryIds.length === 0
                     ? t('settings.userMgmtNoLibraries')
                     : libraries.filter(l => u.libraryIds.includes(l.id)).map(l => l.name).join(', ');
+                const lastSeen = formatLastSeen(u.lastAccessAt, i18n.language, t('settings.userMgmtNeverSeen'));
+                const lastSeenAbsolute = u.lastAccessAt
+                  ? new Date(u.lastAccessAt).toLocaleString(i18n.language)
+                  : '';
                 return (
                   <div
                     key={u.id}
@@ -652,9 +673,15 @@ function UserManagementSection({
                         {libNames}
                       </span>
                     )}
+                    <span
+                      style={{ fontSize: 11, color: 'var(--text-muted)', flexShrink: 0, marginLeft: libNames ? 0 : 'auto' }}
+                      data-tooltip={lastSeenAbsolute || undefined}
+                    >
+                      {lastSeen}
+                    </span>
                     <button
                       className="btn btn-ghost"
-                      style={{ color: 'var(--danger)', padding: '2px 6px', marginLeft: 'auto', flexShrink: 0 }}
+                      style={{ color: 'var(--danger)', padding: '2px 6px', flexShrink: 0 }}
                       onClick={(e) => { e.stopPropagation(); setConfirmingDelete(u); }}
                       disabled={busy || isSelf}
                       data-tooltip={t('settings.userMgmtDelete')}