fix: update innertube clients and fix HLS/DASH quality switching

- Update innertube client versions to match yt-dlp (android 21.02.35,
  ios 21.02.3, web 2.20260114.08.00, android_vr 1.65.10)
- Remove obsolete clients (android-test-suite, ios_vr)
- Replace tv_embedded with TVHTML5_SIMPLY (cn 75)
- Add new clients: web_embedded, mweb, tv
- Fix HLS freeze on quality switch: use nextLevel instead of
  currentLevel, handle bufferStalledError, stream proxy segments
  instead of buffering in memory
- Populate DASH quality selector with actual sources (no Auto)
- Render quality-select empty in template, let JS populate per mode

youtube/templates/watch.html

@@ -75,14 +75,11 @@
             <div class="external-player-controls">
                 <input class="speed" id="speed-control" type="text" title="Video speed">
                 {% if settings.use_video_player < 2 %}
-                <!-- Native player quality selector -->
+                <!-- Quality selector (populated by JS: HLS adds Auto+levels, DASH adds discrete sources) -->
                 <select id="quality-select" autocomplete="off">
-                    <option value="-1" selected>Auto</option>
-                    <!-- Quality options will be populated by HLS -->
                 </select>
                 {% else %}
                 <select id="quality-select" autocomplete="off" style="display: none;">
-                    <!-- Quality options will be populated by HLS -->
                 </select>
                 {% endif %}
                 {% if settings.use_video_player != 2 %}