アイヌ語追加 (#428) (#433)

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

frontend/src/lib/posts.test.ts

@@ -48,6 +48,7 @@ describe ('posts API functions', () => {
     expect (api.apiGet).toHaveBeenCalledWith (
         '/posts',
         {
+          locale: 'ja',
           params: {
             title:                 'title',
             tags:                  'a b',
@@ -89,6 +90,7 @@ describe ('posts API functions', () => {
           original_created_before: '2026-01-02T00:00:00Z',
         },
         {
+          locale: 'ja',
           params: {
             base_version_no: '7',
             force:           '1',
@@ -113,7 +115,7 @@ describe ('posts API functions', () => {
 
     expect (api.apiGet).toHaveBeenCalledWith (
         '/posts/versions',
-        { params: { page: 2, limit: 50 } },
+        { locale: 'ja', params: { page: 2, limit: 50 } },
     )
   })
 
@@ -129,6 +131,7 @@ describe ('posts API functions', () => {
     expect (api.apiGet).toHaveBeenCalledWith (
 	'/posts/versions',
 	{
+	  locale: 'ja',
 	  params: {
 	    external_tag: '7',
 	    page:         2,