feat(stats): add v1 immersion stats dashboard (#19)

src/renderer/yomitan-popup.test.ts

@@ -0,0 +1,18 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { YOMITAN_LOOKUP_EVENT, registerYomitanLookupListener } from './yomitan-popup.js';
+
+test('registerYomitanLookupListener forwards the SubMiner Yomitan lookup event', () => {
+  const target = new EventTarget();
+  const calls: string[] = [];
+
+  const dispose = registerYomitanLookupListener(target, () => {
+    calls.push('lookup');
+  });
+
+  target.dispatchEvent(new CustomEvent(YOMITAN_LOOKUP_EVENT));
+  dispose();
+  target.dispatchEvent(new CustomEvent(YOMITAN_LOOKUP_EVENT));
+
+  assert.deepEqual(calls, ['lookup']);
+});