feat(renderer): video player with HLS.js & YouTube embed (M10.12)

- VideoPlayer.vue: native <video> with custom glass styling
- HLS.js lazy-loaded for adaptive streaming (.m3u8)
- YouTube detection → youtube-nocookie.com embed
- Fullscreen via native controls, playsinline for mobile

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

pnpm-lock.yaml

@@ -27,6 +27,9 @@ importers:
       '@tanstack/vue-virtual':
         specifier: ^3.13.19
         version: 3.13.19(vue@3.5.29(typescript@5.8.3))
+      hls.js:
+        specifier: ^1.6.15
+        version: 1.6.15
       katex:
         specifier: ^0.16.33
         version: 0.16.33
@@ -2295,6 +2298,9 @@ packages:
     resolution: {integrity: sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==}
     engines: {node: '>= 0.4'}
 
+  hls.js@1.6.15:
+    resolution: {integrity: sha512-E3a5VwgXimGHwpRGV+WxRTKeSp2DW5DI5MWv34ulL3t5UNmyJWCQ1KmLEHbYzcfThfXG8amBL+fCYPneGHC4VA==}
+
   hookable@5.5.3:
     resolution: {integrity: sha512-Yc+BQe8SvoXH1643Qez1zqLRmbA5rCL+sSmk6TVos0LWVfNIB7PGncdlId77WzLGSIB5KaWgTaNTs2lNVEI6VQ==}
 
@@ -5899,6 +5905,8 @@ snapshots:
     dependencies:
       function-bind: 1.1.2
 
+  hls.js@1.6.15: {}
+
   hookable@5.5.3: {}
 
   html-entities@2.6.0: {}