feat(brand): official WeVisto logo + linked badge on user-facing pages

- frontend/public/logo.svg: Camogli photo with We[V]isto knockout wordmark
  (yellow V accent), embedded base64 so the SVG is self-contained
- brand/: raw source (15.7MB Camogli original) + 900x900 crop used in the
  SVG, plus a short README documenting both
- Login, register, setup index/configure, help: linked logo badge above
  the page heading
- Email template: logo bumped to 64x64 (was 30 tall — wordmark unreadable)

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

templates/emails/share_notification.html.twig

@@ -5,8 +5,8 @@
   <div style="max-width:480px;margin:0 auto;background:#fff;border-radius:12px;overflow:hidden;border:1px solid #e8d9c4">
     <div style="padding:1.5rem">
       <img src="{{ absolute_url('/build/logo.svg') }}" alt="WeVisto"
-           width="120" height="30"
-           style="display:block;height:30px;width:auto;margin-bottom:.75rem">
+           width="64" height="64"
+           style="display:block;width:64px;height:64px;border-radius:10px;margin-bottom:.75rem">
 
       <h1 style="font-size:1.25rem;font-weight:700;color:#3a2e22;margin-bottom:.5rem">{{ sharer.email }} shared a photo with you</h1>
       <p style="color:#8a7060;font-size:.875rem;margin-bottom:1.25rem">Add it to your frame or decline — it's up to you.</p>