アイヌ語追加 (#428) (#433)

Reviewed-on: #433
Co-authored-by: miteruzo <miteruzo@naver.com>

frontend/src/lib/help.test.ts

@@ -29,7 +29,7 @@ describe ('Help file catalogue', () => {
 	const { api } = createHelpFixture ()
 	expect (api.parseHelpEdition (edition)).toEqual ({ date: '2026-10-02', revision })
 	const date = api.helpEditionDate (edition)!
-	expect ([date.getFullYear (), date.getMonth (), date.getDate ()]).toEqual ([2026, 9, 2])
+	expect (date.toISOString ()).toBe ('2026-10-01T15:00:00.000Z')
       })
 
   it.each (['missing', '2026-02-30', '2026-10-02.0', '2026-10-02.2.extra',
@@ -51,9 +51,9 @@ describe ('Help file catalogue', () => {
     expect ((await api.getHelpArticle ('guide'))?.languages.ja.currentEdition)
 	.toBe ('2026-10-02.10')
     expect (await api.getHelpSearchEntries ('ja')).toEqual ([
-	{ identifier: 'guide', edition: '2026-10-02.10',
+	{ identifier: 'guide', language: 'ja', edition: '2026-10-02.10',
 	  title: 'ホーム第十版', body: '\nタグを検索する 第十版本文' },
-	{ identifier: '設定 手順', edition: '2026-10-03',
+	{ identifier: '設定 手順', language: 'ja', edition: '2026-10-03',
 	  title: '設定', body: '\nタグを設定する' }])
   })
 
@@ -66,6 +66,15 @@ describe ('Help file catalogue', () => {
 	.not.toContain ('2026-10-02.11')
   })
 
+  it ('does not substitute Japanese articles, search or changes for missing Ainu content',
+      async () => {
+	const { api } = createHelpFixture ()
+	const article = await api.getHelpArticle ('guide')
+	expect (api.resolveHelpLanguage (article, 'ain')).toBeNull ()
+	expect (await api.getHelpSearchEntries ('ain')).toEqual ([])
+	expect (await api.getHelpChanges ('ain')).toEqual ([])
+      })
+
   it ('uses generated edition titles without reparsing raw sources', async () => {
     const { api, raw } = createHelpFixture ()
     expect (await api.getHelpEditionText ('guide', 'ja', '2026-10-01'))