fix(boot): clear loading overlay after startup errors

public/boot-guard.js

@@ -0,0 +1,13 @@
+/* Never leave the desktop hidden behind the loading overlay after a script error. */
+(() => {
+  const finish = () => document.querySelector('#boot')?.remove();
+  window.addEventListener('error', event => {
+    console.error('Life OS startup error:', event.error || event.message);
+    finish();
+  });
+  window.addEventListener('unhandledrejection', event => {
+    console.error('Life OS startup rejection:', event.reason);
+    finish();
+  });
+  setTimeout(finish, 1400);
+})();