fix(canvas): [PKG-CANVAS-SUBTITLE-01] attach native subtitle tracks

docs/compiled/artplayer-proxy-canvas.mjs

@@ -204,6 +204,21 @@ function createFrameScheduler(draw, active) {
     }
   };
 }
+function forwardSubtitleTrack(canvas, video, initialTrack, active) {
+  if (!active())
+    return;
+  const append = canvas.appendChild;
+  initialTrack.kind = "metadata";
+  initialTrack.default = true;
+  video.appendChild(initialTrack);
+  canvas.appendChild = (node) => {
+    if (active() && node.nodeType === 1 && node.nodeName === "TRACK" && "namespaceURI" in node && node.namespaceURI === "http://www.w3.org/1999/xhtml") {
+      initialTrack.remove();
+      return video.appendChild(node);
+    }
+    return append.call(canvas, node);
+  };
+}
 function artplayerProxyCanvas(callback) {
   return (art) => {
     const constructor = art.constructor;
@@ -262,6 +277,7 @@ function artplayerProxyCanvas(callback) {
         scheduler.request();
     }
     try {
+      forwardSubtitleTrack(canvas, video, constructor.utils.createElement("track"), active);
       listen("destroy", destroy);
       listen("video:loadedmetadata", () => {
         if (hasDimensions(video)) {