feat(i18n): add Russian language support

packages/cli/src/ui/commands/languageCommand.ts

@@ -130,6 +130,7 @@ async function setUiLanguage(
   const langDisplayNames: Record<SupportedLanguage, string> = {
     zh: '中文（zh-CN）',
     en: 'English（en-US）',
+    ru: 'Русский (ru-RU)',
   };
 
   return {
@@ -216,7 +217,7 @@ export const languageCommand: SlashCommand = {
           : t('LLM output language not set'),
         '',
         t('Available subcommands:'),
-        `  /language ui [zh-CN|en-US] - ${t('Set UI language')}`,
+        `  /language ui [zh-CN|en-US|ru-RU] - ${t('Set UI language')}`,
         `  /language output <language> - ${t('Set LLM output language')}`,
       ].join('\n');
 
@@ -232,7 +233,7 @@ export const languageCommand: SlashCommand = {
     const subcommand = parts[0].toLowerCase();
 
     if (subcommand === 'ui') {
-      // Handle /language ui [zh-CN|en-US]
+      // Handle /language ui [zh-CN|en-US|ru-RU]
       if (parts.length === 1) {
         // Show UI language subcommand help
         return {
@@ -241,11 +242,12 @@ export const languageCommand: SlashCommand = {
           content: [
             t('Set UI language'),
             '',
-            t('Usage: /language ui [zh-CN|en-US]'),
+            t('Usage: /language ui [zh-CN|en-US|ru-RU]'),
             '',
             t('Available options:'),
             t('  - zh-CN: Simplified Chinese'),
             t('  - en-US: English'),
+            t('  - ru-RU: Russian'),
             '',
             t(
               'To request additional UI language packs, please open an issue on GitHub.',
@@ -266,11 +268,18 @@ export const languageCommand: SlashCommand = {
         langArg === 'zh-cn'
       ) {
         targetLang = 'zh';
+      } else if (
+        langArg === 'ru' ||
+        langArg === 'ru-RU' ||
+        langArg === 'russian' ||
+        langArg === 'русский'
+      ) {
+        targetLang = 'ru';
       } else {
         return {
           type: 'message',
           messageType: 'error',
-          content: t('Invalid language. Available: en-US, zh-CN'),
+          content: t('Invalid language. Available: en-US, zh-CN, ru-RU'),
         };
       }
 
@@ -307,13 +316,20 @@ export const languageCommand: SlashCommand = {
         langArg === 'zh-cn'
       ) {
         targetLang = 'zh';
+      } else if (
+        langArg === 'ru' ||
+        langArg === 'ru-RU' ||
+        langArg === 'russian' ||
+        langArg === 'русский'
+      ) {
+        targetLang = 'ru';
       } else {
         return {
           type: 'message',
           messageType: 'error',
           content: [
             t('Invalid command. Available subcommands:'),
-            '  - /language ui [zh-CN|en-US] - ' + t('Set UI language'),
+            '  - /language ui [zh-CN|en-US|ru-RU] - ' + t('Set UI language'),
             '  - /language output <language> - ' + t('Set LLM output language'),
           ].join('\n'),
         };
@@ -423,6 +439,29 @@ export const languageCommand: SlashCommand = {
             return setUiLanguage(context, 'en');
           },
         },
+        {
+          name: 'ru-RU',
+          altNames: ['ru', 'russian', 'русский'],
+          get description() {
+            return t('Set UI language to Russian (ru-RU)');
+          },
+          kind: CommandKind.BUILT_IN,
+          action: async (
+            context: CommandContext,
+            args: string,
+          ): Promise<MessageActionReturn> => {
+            if (args.trim().length > 0) {
+              return {
+                type: 'message',
+                messageType: 'error',
+                content: t(
+                  'Language subcommands do not accept additional arguments.',
+                ),
+              };
+            }
+            return setUiLanguage(context, 'ru');
+          },
+        },
       ],
     },
     {