feat(language): add Japanese language support to LanguageSelector and i18n configuration (#2131)

web/src/components/layout/headerbar/LanguageSelector.jsx

@@ -20,7 +20,7 @@ For commercial licensing, please contact support@quantumnous.com
 import React from 'react';
 import React from 'react';
 import { Button, Dropdown } from '@douyinfe/semi-ui';
 import { Button, Dropdown } from '@douyinfe/semi-ui';
 import { Languages } from 'lucide-react';
 import { Languages } from 'lucide-react';
-import { CN, GB, FR, RU } from 'country-flag-icons/react/3x2';
+import { CN, GB, FR, RU, JP } from 'country-flag-icons/react/3x2';
 
 
 const LanguageSelector = ({ currentLang, onLanguageChange, t }) => {
 const LanguageSelector = ({ currentLang, onLanguageChange, t }) => {
   return (
   return (
@@ -28,6 +28,7 @@ const LanguageSelector = ({ currentLang, onLanguageChange, t }) => {
       position='bottomRight'
       position='bottomRight'
       render={
       render={
         <Dropdown.Menu className='!bg-semi-color-bg-overlay !border-semi-color-border !shadow-lg !rounded-lg dark:!bg-gray-700 dark:!border-gray-600'>
         <Dropdown.Menu className='!bg-semi-color-bg-overlay !border-semi-color-border !shadow-lg !rounded-lg dark:!bg-gray-700 dark:!border-gray-600'>
+          {/* Language sorting: Order by English name (Chinese, English, French, Japanese, Russian) */}
           <Dropdown.Item
           <Dropdown.Item
             onClick={() => onLanguageChange('zh')}
             onClick={() => onLanguageChange('zh')}
             className={`!flex !items-center !gap-2 !px-3 !py-1.5 !text-sm !text-semi-color-text-0 dark:!text-gray-200 ${currentLang === 'zh' ? '!bg-semi-color-primary-light-default dark:!bg-blue-600 !font-semibold' : 'hover:!bg-semi-color-fill-1 dark:hover:!bg-gray-600'}`}
             className={`!flex !items-center !gap-2 !px-3 !py-1.5 !text-sm !text-semi-color-text-0 dark:!text-gray-200 ${currentLang === 'zh' ? '!bg-semi-color-primary-light-default dark:!bg-blue-600 !font-semibold' : 'hover:!bg-semi-color-fill-1 dark:hover:!bg-gray-600'}`}
@@ -50,6 +51,14 @@ const LanguageSelector = ({ currentLang, onLanguageChange, t }) => {
             <span>Français</span>
             <span>Français</span>
           </Dropdown.Item>
           </Dropdown.Item>
           <Dropdown.Item
           <Dropdown.Item
+            onClick={() => onLanguageChange('ja')}
+            className={`!flex !items-center !gap-2 !px-3 !py-1.5 !text-sm !text-semi-color-text-0 dark:!text-gray-200 ${currentLang === 'ja' ? '!bg-semi-color-primary-light-default dark:!bg-blue-600 !font-semibold' : 'hover:!bg-semi-color-fill-1 dark:hover:!bg-gray-600'}`}
+          >
+            {/* Japanese flag using emoji as country-flag-icons/react/3x2 does not export JP */}
+            <JP title='日本語' className='!w-5 !h-auto' />
+            <span>日本語</span>
+          </Dropdown.Item>
+          <Dropdown.Item
             onClick={() => onLanguageChange('ru')}
             onClick={() => onLanguageChange('ru')}
             className={`!flex !items-center !gap-2 !px-3 !py-1.5 !text-sm !text-semi-color-text-0 dark:!text-gray-200 ${currentLang === 'ru' ? '!bg-semi-color-primary-light-default dark:!bg-blue-600 !font-semibold' : 'hover:!bg-semi-color-fill-1 dark:hover:!bg-gray-600'}`}
             className={`!flex !items-center !gap-2 !px-3 !py-1.5 !text-sm !text-semi-color-text-0 dark:!text-gray-200 ${currentLang === 'ru' ? '!bg-semi-color-primary-light-default dark:!bg-blue-600 !font-semibold' : 'hover:!bg-semi-color-fill-1 dark:hover:!bg-gray-600'}`}
           >
           >

web/src/i18n/i18n.js

@@ -25,6 +25,7 @@ import enTranslation from './locales/en.json';
 import frTranslation from './locales/fr.json';
 import frTranslation from './locales/fr.json';
 import zhTranslation from './locales/zh.json';
 import zhTranslation from './locales/zh.json';
 import ruTranslation from './locales/ru.json';
 import ruTranslation from './locales/ru.json';
+import jaTranslation from './locales/ja.json';
 
 
 i18n
 i18n
   .use(LanguageDetector)
   .use(LanguageDetector)
@@ -36,6 +37,7 @@ i18n
       zh: zhTranslation,
       zh: zhTranslation,
       fr: frTranslation,
       fr: frTranslation,
       ru: ruTranslation,
       ru: ruTranslation,
+      ja: jaTranslation,
     },
     },
     fallbackLng: 'zh',
     fallbackLng: 'zh',
     interpolation: {
     interpolation: {