fix(excalidraw): fusion imports ESM en un seul module + CSP worker-src/blob:

frontend/excalidraw-editor.html

@@ -89,18 +89,15 @@
     <button id="btn-export-svg" title="Export SVG">📐 SVG</button>
   </div>
 
-  <!-- Import React + ReactDOM (Excalidraw peer dependencies) -->
+  <!-- Import React, ReactDOM, and Excalidraw in a single module (order matters!) -->
   <script type="module">
     import React from "https://esm.sh/react@18";
     import ReactDOM from "https://esm.sh/react-dom@18";
+    import * as ExcalidrawLib from "https://esm.sh/@excalidraw/[email protected]";
+
     window.React = React;
     window.ReactDOM = ReactDOM;
-  </script>
-
-  <!-- Configure Excalidraw asset path BEFORE import -->
-  <script type="module">
     window.EXCALIDRAW_ASSET_PATH = "https://esm.sh/@excalidraw/[email protected]/dist/prod/";
-    import * as ExcalidrawLib from "https://esm.sh/@excalidraw/[email protected]";
     window.ExcalidrawLib = ExcalidrawLib;
 
     const { Excalidraw, exportToBlob, exportToSvg } = ExcalidrawLib;