fix: convert ES modules to classic scripts for file:// compatibility

Browsers block ES module imports over the file:// protocol due to CORS.
Users opening the overlay by double-clicking the HTML file saw all JS
fail to load. Replace import/export with a window.OBS global namespace
and classic <script> tags so the overlay works without a local server.

Made-with: Cursor

js/player-list.js

@@ -39,7 +39,7 @@ function displayName(p) {
   return String(p).trim();
 }
 
-export class PlayerList {
+class PlayerList {
   constructor() {
     this._active = false;
     /** @type {HTMLElement | null} */
@@ -315,3 +315,6 @@ export class PlayerList {
     this._animationTimers = [];
   }
 }
+
+window.OBS = window.OBS || {};
+window.OBS.PlayerList = PlayerList;