v12: Fix DVR — use hls.liveSyncPosition for initial seek

Refinement: Use hls.liveSyncPosition (calculated from playlist) instead of video.duration for initial live edge seek. More reliable since video.duration depends on buffer state.

static/yt_live.js

@@ -860,9 +860,16 @@
       // v12: After manifest loaded, seek to live edge first, then play
       hls.on(Hls.Events.MANIFEST_PARSED,(ev,data)=>{
         loadEl.style.display='none';video.style.display='block';
-        // Seek to live edge manually since we disabled auto-sync
-        const dur = video.duration;
-        if(dur && isFinite(dur)){ video.currentTime = dur; }
+        // Seek to live edge using hls.liveSyncPosition (calculated from playlist)
+        // Works even with liveSyncDurationCount:0 since it's just a position reference
+        const livePos = hls.liveSyncPosition;
+        if(livePos && isFinite(livePos) && livePos > 0){
+          video.currentTime = livePos;
+        } else {
+          // Fallback: use video.duration
+          const dur = video.duration;
+          if(dur && isFinite(dur)){ video.currentTime = dur; }
+        }
         video.play().catch(()=>{});
       });