feat(a11y,admin): skip link, aria-labels, Ready label, title + age fixes

A11y:
- Skip-to-content link lands first in the body and jumps to #main
  past the header + sidebar for keyboard users.
- aria-label on the icon buttons that previously carried only an
  icon: hamburger menu (+ aria-controls="sidebar"), mobile search
  toggle, account menu (also drops the duplicate alt on the avatar
  since the button name already speaks the user's name).

Admin:
- Dashboard stat card renamed "Live Videos" → "Ready" (matches the
  DB status column; nothing on this card is actually live).

Settings:
- Duplicate "Prefer not to say" option on the Gender select — the
  empty placeholder shared the same label as the real option.
  Placeholder is now "Select…"; the real "Prefer not to say" option
  stays unchanged.
- Birthday picker caps the Year dropdown at (this year − 13) and
  the server-side register validation requires the same, so a
  client bypass can't let a <13 user through.

Titles:
- Admin layout uses "{Page} | TAKEONE" to match the frontend format
  (was "{Page} — TAKEONE"). User pages that said "| TAKEONE" literal
  now interpolate config('app.name'). Shorts and Welcome moved from
  " - " to " | " separator.

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>

app/Http/Controllers/Auth/RegisteredUserController.php

@@ -32,7 +32,11 @@ class RegisteredUserController extends Controller
             'name'        => ['required', 'string', 'max:255', new ReservedIdentifier('name')],
             'email'       => ['required', 'string', 'email', 'max:255', 'unique:users', new NotDisposableEmail, new ReservedIdentifier('email')],
             'password'    => ['required', 'confirmed', Password::defaults()],
-            'birthday'    => ['required', 'date', 'before:today'],
+            // Age gate: must be at least 13 on sign-up day. The front-end
+            // date picker already caps the year dropdown, but the server
+            // must enforce it so a client bypass doesn't let a 10-year-old
+            // through.
+            'birthday'    => ['required', 'date', 'before:' . now()->subYears(13)->toDateString()],
             'gender'      => ['required', 'in:male,female'],
             'nationality' => ['required', 'string', 'size:2'],
         ]);