Language filter chips on the videos feed

Adds one chip per language currently present in public content —
counting both primary language and any secondary audio track, sorted
by video count, capped at 12. Clicking a chip lists every video whose
primary is that language or that has a matching secondary track; cards
surfaced only via a secondary track link straight to /videos/{key}?track=<id>
so the pinned playback wiring loads the right audio, get a small flag
badge on the thumbnail, and their hover-preview streams the track file
instead of the primary.

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

resources/views/videos/index.blade.php

@@ -34,6 +34,10 @@
 
     .yt-empty { text-align: center; padding: 80px 20px; }
 
+    /* Language chips */
+    .yt-chip-sep { display:inline-block; width:1px; align-self:stretch; margin:6px 4px; background:var(--border-color); }
+    .yt-chip-lang { display:inline-flex; align-items:center; gap:6px; }
+    .yt-chip-lang .fi { width:18px; height:13px; border-radius:2px; display:inline-block; flex-shrink:0; }
 </style>
 @endsection
 
@@ -57,6 +61,19 @@
        class="yt-chip {{ $activeFilter === 'playlists' ? 'active' : '' }}">Playlists</a>
     <a href="{{ route('videos.index', ['filter' => 'latest']) }}"
        class="yt-chip {{ $activeFilter === 'latest' ? 'active' : '' }}">New to You</a>
+
+    @if(!empty($langChips ?? []))
+        @php $activeLang = str_starts_with($activeFilter, 'lang:') ? substr($activeFilter, 5) : null; @endphp
+        <span class="yt-chip-sep" aria-hidden="true"></span>
+        @foreach($langChips as $chip)
+            <a href="{{ route('videos.index', ['filter' => 'lang:' . $chip['code']]) }}"
+               class="yt-chip yt-chip-lang {{ $activeLang === $chip['code'] ? 'active' : '' }}"
+               title="{{ $chip['name'] }} ({{ $chip['count'] }})">
+                <span class="fi fi-{{ $chip['flag'] }}"></span>
+                <span>{{ $chip['name'] }}</span>
+            </a>
+        @endforeach
+    @endif
 </div>
 @endunless