Settings: hidden Admin entry (opens /admin in the app window); admin page keeps a back link on phones

frontend/views-core.js

@@ -1074,6 +1074,15 @@ async function renderSettings() {
         </span>
         <span id="aboutBuildTime" class="about-version">…</span>
       </div>
+      <div class="set-row hidden" id="aboutAdminRow">
+        <span>
+          Admin
+          <small>Lyrics studio, reports, library and server tools. Needs the admin password.</small>
+        </span>
+        <div class="set-actions" style="margin:0">
+          <a class="btn" href="/admin" id="aboutAdminLink" style="text-decoration:none;display:inline-flex;align-items:center">Open admin</a>
+        </div>
+      </div>
     </div>`;
 
   c.appendChild(wrap);
@@ -1456,6 +1465,34 @@ async function renderSettings() {
   });
   updateProfileStatus();
 
+  // ---- About: Admin entry. Shown once this device has signed in as admin,
+  // or after a long-press / five taps on the version (then remembered). It
+  // opens /admin inside the app window, which has no address bar on iPhone.
+  if (WEB) {
+    const ADMIN_KEY = 'ytpAdminEntry';
+    const revealAdmin = (remember) => {
+      const row = $('aboutAdminRow');
+      if (row) row.classList.remove('hidden');
+      if (remember) { try { localStorage.setItem(ADMIN_KEY, '1'); } catch {} }
+    };
+    try { if (localStorage.getItem(ADMIN_KEY) === '1') revealAdmin(false); } catch {}
+    fetch('/api/admin/me', { cache: 'no-store', credentials: 'same-origin' })
+      .then((r) => (r.ok ? r.json() : null)).then((me) => { if (me && me.admin) revealAdmin(true); }).catch(() => {});
+    const ver = $('aboutVersion');
+    if (ver) {
+      let taps = 0, tapTimer = null, holdTimer = null;
+      const unlock = () => { if ($('aboutAdminRow')?.classList.contains('hidden')) { revealAdmin(true); toast('Admin entry shown in About'); } };
+      ver.addEventListener('pointerdown', () => { clearTimeout(holdTimer); holdTimer = setTimeout(unlock, 700); });
+      for (const n of ['pointerup', 'pointerleave', 'pointercancel']) ver.addEventListener(n, () => clearTimeout(holdTimer));
+      ver.addEventListener('click', () => {
+        taps++; clearTimeout(tapTimer); tapTimer = setTimeout(() => { taps = 0; }, 1500);
+        if (taps >= 5) { taps = 0; unlock(); }
+      });
+      ver.addEventListener('contextmenu', (e) => e.preventDefault());
+      ver.style.webkitUserSelect = 'none'; ver.style.userSelect = 'none';
+    }
+  }
+
   // ---- About: append server build tag + build time (WEB mode only) ----
   if (WEB) {
     try {