Fix nested Yomitan popup focus loss

src/renderer/error-recovery.test.ts

@@ -3,7 +3,9 @@ import assert from 'node:assert/strict';
 
 import { createRendererRecoveryController } from './error-recovery.js';
 import {
+  YOMITAN_POPUP_HOST_SELECTOR,
   YOMITAN_POPUP_IFRAME_SELECTOR,
+  YOMITAN_POPUP_VISIBLE_HOST_SELECTOR,
   hasYomitanPopupIframe,
   isYomitanPopupIframe,
   isYomitanPopupVisible,
@@ -284,9 +286,25 @@ test('hasYomitanPopupIframe queries for modern + legacy selector', () => {
   assert.equal(selector, YOMITAN_POPUP_IFRAME_SELECTOR);
 });
 
+test('hasYomitanPopupIframe falls back to popup host selector for shadow-hosted popups', () => {
+  const selectors: string[] = [];
+  const root = {
+    querySelector: (value: string) => {
+      selectors.push(value);
+      if (value === YOMITAN_POPUP_HOST_SELECTOR) {
+        return {};
+      }
+      return null;
+    },
+  } as unknown as ParentNode;
+
+  assert.equal(hasYomitanPopupIframe(root), true);
+  assert.deepEqual(selectors, [YOMITAN_POPUP_IFRAME_SELECTOR, YOMITAN_POPUP_HOST_SELECTOR]);
+});
+
 test('isYomitanPopupVisible requires visible iframe geometry', () => {
   const previousWindow = (globalThis as { window?: unknown }).window;
-  let selector = '';
+  const selectors: string[] = [];
   const visibleFrame = {
     getBoundingClientRect: () => ({ width: 320, height: 180 }),
   } as unknown as HTMLIFrameElement;
@@ -309,18 +327,40 @@ test('isYomitanPopupVisible requires visible iframe geometry', () => {
   try {
     const root = {
       querySelectorAll: (value: string) => {
-        selector = value;
+        selectors.push(value);
+        if (value === YOMITAN_POPUP_VISIBLE_HOST_SELECTOR || value === YOMITAN_POPUP_HOST_SELECTOR) {
+          return [];
+        }
         return [hiddenFrame, visibleFrame];
       },
     } as unknown as ParentNode;
 
     assert.equal(isYomitanPopupVisible(root), true);
-    assert.equal(selector, YOMITAN_POPUP_IFRAME_SELECTOR);
+    assert.deepEqual(selectors, [
+      YOMITAN_POPUP_VISIBLE_HOST_SELECTOR,
+      YOMITAN_POPUP_IFRAME_SELECTOR,
+    ]);
   } finally {
     Object.defineProperty(globalThis, 'window', { configurable: true, value: previousWindow });
   }
 });
 
+test('isYomitanPopupVisible detects visible shadow-hosted popup marker without iframe access', () => {
+  let selector = '';
+  const root = {
+    querySelectorAll: (value: string) => {
+      selector = value;
+      if (value === YOMITAN_POPUP_VISIBLE_HOST_SELECTOR) {
+        return [{ getAttribute: () => 'true' }];
+      }
+      return [];
+    },
+  } as unknown as ParentNode;
+
+  assert.equal(isYomitanPopupVisible(root), true);
+  assert.equal(selector, YOMITAN_POPUP_VISIBLE_HOST_SELECTOR);
+});
+
 test('scrollActiveRuntimeOptionIntoView scrolls active runtime option with nearest block', () => {
   const calls: Array<{ block?: ScrollLogicalPosition }> = [];
   const activeItem = {