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]>

resources/views/auth/register.blade.php

@@ -38,7 +38,10 @@
         </div>
 
         <div class="form-group">
-            <x-date-picker name="birthday" label="Date of Birth" :value="old('birthday')" required />
+            {{-- COPPA / platform minimum age: 13 at sign-up. maxYear caps
+                 the year dropdown at (this year − 13). --}}
+            <x-date-picker name="birthday" label="Date of Birth" :value="old('birthday')"
+                           :max-year="(int) date('Y') - 13" required />
         </div>
 
         <div class="form-group">