Fix logo visibility: use auto width for horizontal image, rename to WBfeed

- topbar: height:28px width:auto (fits 4:1 logo without squishing)
- login brand icon: white rectangular bg, height:36px width:auto
- auth-kicker: height:24px width:auto
- Brand name: WBfeed everywhere

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/index.html

@@ -12,7 +12,7 @@
     <div class="topbar__inner">
         <a href="{{ url_for('index') }}" class="topbar__brand">
             <img src="{{ url_for('static', filename='wb3.png') }}" class="topbar__logo-img" alt="WB">
-            <span class="topbar__name">WBfeed.ru</span>
+            <span class="topbar__name">WBfeed</span>
         </a>
         <div class="topbar__nav">
             <a href="{{ url_for('index') }}" class="topbar__link active">Отзывы</a>