fix: use Tone.js global object from CDN instead of ES module import

- Remove ES module import statement from dashboard.js
- Use global Tone object loaded via CDN
- Remove type=module from script tag
- Fixes module resolution error

public/dashboard.js

@@ -1,5 +1,4 @@
-import * as Tone from 'tone';
-
+// Tone.js loaded via CDN as global object
 const bootstrapData = JSON.parse(document.getElementById('__DASHBOARD_DATA__')?.textContent || '{}');
 const state = {
   socket: null,