Run onConnect callback just once. Fixes #1191.

Author: derekkraan

packages/vidstack/src/elements/define/sliders/slider-chapters-element.ts

@@ -26,8 +26,14 @@ export class MediaSliderChaptersElement extends Host(HTMLElement, SliderChapters
   static tagName = 'media-slider-chapters';
 
   #template: HTMLTemplateElement | null = null;
+  #connectedRanOnce: Boolean = false;
 
   protected onConnect(): void {
+    // onConnect can run more than once (eg, Phoenix LiveView after navigation)
+    if (this.#connectedRanOnce) return;
+
+    this.#connectedRanOnce = true;
+
     // Animation frame required as some frameworks append late for some reason.
     requestScopedAnimationFrame(() => {
       if (!this.connectScope) return;