feat: Implement basic general folder support (#2051)

- Related: #1748

tests/ha/fire-hass-event.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it, vi } from 'vitest';
+import { fireHASSEvent } from '../../src/ha/fire-hass-event';
+
+// @vitest-environment jsdom
+describe('fireHASSEvent', () => {
+  it('should fire an event with specified type and detail', () => {
+    const target = document.createElement('div');
+    const handler = vi.fn();
+
+    const type = 'll-custom';
+    const detail = { action: 'test' };
+
+    target.addEventListener(type, handler);
+
+    fireHASSEvent(target, type, detail);
+
+    expect(handler).toBeCalledWith(
+      expect.objectContaining({
+        detail,
+      }),
+    );
+  });
+});