Show bitrate in browser, remove type labels and Play All text

- Extract bitrate alongside duration in browse_directory via get_media_info
- Display bitrate in large card view metadata (duration · bitrate · size)
- Replace Audio/Video type badge with bitrate column in list view
- Remove Play All button text, keep icon only
- Add formatBitrate helper function

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

media_server/static/index.html

@@ -193,7 +193,6 @@
                     </button>
                     <button class="browser-play-all-btn" id="playAllBtn" onclick="playAllFolder()" data-i18n-title="browser.play_all" title="Play All" style="display: none;">
                         <svg viewBox="0 0 24 24" width="16" height="16"><path fill="currentColor" d="M8 5v14l11-7z"/></svg>
-                        <span data-i18n="browser.play_all">Play All</span>
                     </button>
                 </div>
                 <div class="browser-search-wrapper" id="browserSearchWrapper" style="display: none;">