feat: complete internationalization (i18n) for components

Implemented comprehensive i18n translation support for the following components:

1. GitSettings.jsx - Git configuration interface
2. ApiKeysSettings.jsx - API keys settings
3. CredentialsSettings.jsx - Credentials settings (GitHub tokens)
4. TasksSettings.jsx - TaskMaster task management settings
5. ChatInterface.jsx - Chat interface (major translation work)

New translation files:
- src/i18n/locales/en/chat.json - English chat interface translations
- src/i18n/locales/zh-CN/chat.json - Chinese chat interface translations

ChatInterface.jsx translations:
- Code block copy buttons (Copy, Copied, Copy code)
- Message type labels (User, Error, Tool, Claude, Cursor, Codex)
- Tool settings tooltip
- Search result display (pattern, in, results)
- Codex permission modes (Default, Accept Edits, Bypass Permissions, Plan)
- Input placeholder and hint text
- Keyboard shortcut hints (Ctrl+Enter/Enter modes)
- Command menu button

i18n configuration updates:
- Registered chat namespace in config.js
- Extended settings.json translations (git, apiKeys, tasks, agents, mcpServers sections)

完成以下组件的 i18n 翻译工作：

1. GitSettings.jsx - Git 配置界面
2. ApiKeysSettings.jsx - API 密钥设置
3. CredentialsSettings.jsx - 凭据设置（GitHub Token）
4. TasksSettings.jsx - TaskMaster 任务管理设置
5. ChatInterface.jsx - 聊天界面（主要翻译工作）

新增翻译文件：
- src/i18n/locales/en/chat.json - 英文聊天界面翻译
- src/i18n/locales/zh-CN/chat.json - 中文聊天界面翻译

ChatInterface.jsx 翻译内容：
- 代码块复制按钮
- 消息类型标签
- 工具设置提示
- 搜索结果显示
- Codex 权限模式（默认、编辑、无限制、计划模式）
- 输入框占位符和提示文本
- 键盘快捷键提示
- 命令菜单按钮

更新 i18n 配置：
- 在 config.js 中注册 chat 命名空间
- 扩展 settings.json 翻译（git、apiKeys、tasks、agents、mcpServers 等部分）

src/components/settings/McpServersContent.jsx

@@ -3,6 +3,7 @@ import { Button } from '../ui/button';
 import { Input } from '../ui/input';
 import { Badge } from '../ui/badge';
 import { Server, Plus, Edit3, Trash2, Terminal, Globe, Zap, X } from 'lucide-react';
+import { useTranslation } from 'react-i18next';
 
 const getTransportIcon = (type) => {
   switch (type) {
@@ -25,16 +26,17 @@ function ClaudeMcpServers({
   serverTools,
   toolsLoading,
 }) {
+  const { t } = useTranslation('settings');
   return (
     <div className="space-y-4">
       <div className="flex items-center gap-3">
         <Server className="w-5 h-5 text-purple-500" />
         <h3 className="text-lg font-medium text-foreground">
-          MCP Servers
+          {t('mcpServers.title')}
         </h3>
       </div>
       <p className="text-sm text-muted-foreground">
-        Model Context Protocol servers provide additional tools and data sources to Claude
+        {t('mcpServers.description.claude')}
       </p>
 
       <div className="flex justify-between items-center">
@@ -44,7 +46,7 @@ function ClaudeMcpServers({
           size="sm"
         >
           <Plus className="w-4 h-4 mr-2" />
-          Add MCP Server
+          {t('mcpServers.addButton')}
         </Button>
       </div>
 
@@ -60,19 +62,19 @@ function ClaudeMcpServers({
                     {server.type}
                   </Badge>
                   <Badge variant="outline" className="text-xs">
-                    {server.scope === 'local' ? 'local' : server.scope === 'user' ? 'user' : server.scope}
+                    {server.scope === 'local' ? t('mcpServers.scope.local') : server.scope === 'user' ? t('mcpServers.scope.user') : server.scope}
                   </Badge>
                 </div>
 
                 <div className="text-sm text-muted-foreground space-y-1">
                   {server.type === 'stdio' && server.config?.command && (
-                    <div>Command: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
+                    <div>{t('mcpServers.config.command')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
                   )}
                   {(server.type === 'sse' || server.type === 'http') && server.config?.url && (
-                    <div>URL: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.url}</code></div>
+                    <div>{t('mcpServers.config.url')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.url}</code></div>
                   )}
                   {server.config?.args && server.config.args.length > 0 && (
-                    <div>Args: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.args.join(' ')}</code></div>
+                    <div>{t('mcpServers.config.args')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.args.join(' ')}</code></div>
                   )}
                 </div>
 
@@ -90,13 +92,13 @@ function ClaudeMcpServers({
                 {/* Tools Discovery Results */}
                 {serverTools?.[server.id] && serverTools[server.id].tools?.length > 0 && (
                   <div className="mt-2 p-2 rounded text-xs bg-blue-50 dark:bg-blue-900/20 text-blue-800 dark:text-blue-200">
-                    <div className="font-medium">Tools ({serverTools[server.id].tools.length}):</div>
+                    <div className="font-medium">{t('mcpServers.tools.title')} {t('mcpServers.tools.count', { count: serverTools[server.id].tools.length })}</div>
                     <div className="flex flex-wrap gap-1 mt-1">
                       {serverTools[server.id].tools.slice(0, 5).map((tool, i) => (
                         <code key={i} className="bg-blue-100 dark:bg-blue-800 px-1 rounded">{tool.name}</code>
                       ))}
                       {serverTools[server.id].tools.length > 5 && (
-                        <span className="text-xs opacity-75">+{serverTools[server.id].tools.length - 5} more</span>
+                        <span className="text-xs opacity-75">{t('mcpServers.tools.more', { count: serverTools[server.id].tools.length - 5 })}</span>
                       )}
                     </div>
                   </div>
@@ -109,7 +111,7 @@ function ClaudeMcpServers({
                   variant="ghost"
                   size="sm"
                   className="text-gray-600 hover:text-gray-700"
-                  title="Edit server"
+                  title={t('mcpServers.actions.edit')}
                 >
                   <Edit3 className="w-4 h-4" />
                 </Button>
@@ -118,7 +120,7 @@ function ClaudeMcpServers({
                   variant="ghost"
                   size="sm"
                   className="text-red-600 hover:text-red-700"
-                  title="Delete server"
+                  title={t('mcpServers.actions.delete')}
                 >
                   <Trash2 className="w-4 h-4" />
                 </Button>
@@ -128,7 +130,7 @@ function ClaudeMcpServers({
         ))}
         {servers.length === 0 && (
           <div className="text-center py-8 text-gray-500 dark:text-gray-400">
-            No MCP servers configured
+            {t('mcpServers.empty')}
           </div>
         )}
       </div>
@@ -138,16 +140,17 @@ function ClaudeMcpServers({
 
 // Cursor MCP Servers
 function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
+  const { t } = useTranslation('settings');
   return (
     <div className="space-y-4">
       <div className="flex items-center gap-3">
         <Server className="w-5 h-5 text-purple-500" />
         <h3 className="text-lg font-medium text-foreground">
-          MCP Servers
+          {t('mcpServers.title')}
         </h3>
       </div>
       <p className="text-sm text-muted-foreground">
-        Model Context Protocol servers provide additional tools and data sources to Cursor
+        {t('mcpServers.description.cursor')}
       </p>
 
       <div className="flex justify-between items-center">
@@ -157,7 +160,7 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
           size="sm"
         >
           <Plus className="w-4 h-4 mr-2" />
-          Add MCP Server
+          {t('mcpServers.addButton')}
         </Button>
       </div>
 
@@ -173,7 +176,7 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
                 </div>
                 <div className="text-sm text-muted-foreground">
                   {server.config?.command && (
-                    <div>Command: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
+                    <div>{t('mcpServers.config.command')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
                   )}
                 </div>
               </div>
@@ -183,6 +186,7 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
                   variant="ghost"
                   size="sm"
                   className="text-gray-600 hover:text-gray-700"
+                  title={t('mcpServers.actions.edit')}
                 >
                   <Edit3 className="w-4 h-4" />
                 </Button>
@@ -191,6 +195,7 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
                   variant="ghost"
                   size="sm"
                   className="text-red-600 hover:text-red-700"
+                  title={t('mcpServers.actions.delete')}
                 >
                   <Trash2 className="w-4 h-4" />
                 </Button>
@@ -200,7 +205,7 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
         ))}
         {servers.length === 0 && (
           <div className="text-center py-8 text-gray-500 dark:text-gray-400">
-            No MCP servers configured
+            {t('mcpServers.empty')}
           </div>
         )}
       </div>
@@ -210,16 +215,17 @@ function CursorMcpServers({ servers, onAdd, onEdit, onDelete }) {
 
 // Codex MCP Servers
 function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
+  const { t } = useTranslation('settings');
   return (
     <div className="space-y-4">
       <div className="flex items-center gap-3">
         <Server className="w-5 h-5 text-gray-700 dark:text-gray-300" />
         <h3 className="text-lg font-medium text-foreground">
-          MCP Servers
+          {t('mcpServers.title')}
         </h3>
       </div>
       <p className="text-sm text-muted-foreground">
-        Model Context Protocol servers provide additional tools and data sources to Codex
+        {t('mcpServers.description.codex')}
       </p>
 
       <div className="flex justify-between items-center">
@@ -229,7 +235,7 @@ function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
           size="sm"
         >
           <Plus className="w-4 h-4 mr-2" />
-          Add MCP Server
+          {t('mcpServers.addButton')}
         </Button>
       </div>
 
@@ -246,13 +252,13 @@ function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
 
                 <div className="text-sm text-muted-foreground space-y-1">
                   {server.config?.command && (
-                    <div>Command: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
+                    <div>{t('mcpServers.config.command')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.command}</code></div>
                   )}
                   {server.config?.args && server.config.args.length > 0 && (
-                    <div>Args: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.args.join(' ')}</code></div>
+                    <div>{t('mcpServers.config.args')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{server.config.args.join(' ')}</code></div>
                   )}
                   {server.config?.env && Object.keys(server.config.env).length > 0 && (
-                    <div>Environment: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{Object.entries(server.config.env).map(([k, v]) => `${k}=${v}`).join(', ')}</code></div>
+                    <div>{t('mcpServers.config.environment')}: <code className="bg-gray-100 dark:bg-gray-800 px-1 rounded text-xs">{Object.entries(server.config.env).map(([k, v]) => `${k}=${v}`).join(', ')}</code></div>
                   )}
                 </div>
               </div>
@@ -263,7 +269,7 @@ function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
                   variant="ghost"
                   size="sm"
                   className="text-gray-600 hover:text-gray-700"
-                  title="Edit server"
+                  title={t('mcpServers.actions.edit')}
                 >
                   <Edit3 className="w-4 h-4" />
                 </Button>
@@ -272,7 +278,7 @@ function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
                   variant="ghost"
                   size="sm"
                   className="text-red-600 hover:text-red-700"
-                  title="Delete server"
+                  title={t('mcpServers.actions.delete')}
                 >
                   <Trash2 className="w-4 h-4" />
                 </Button>
@@ -282,17 +288,16 @@ function CodexMcpServers({ servers, onAdd, onEdit, onDelete }) {
         ))}
         {servers.length === 0 && (
           <div className="text-center py-8 text-gray-500 dark:text-gray-400">
-            No MCP servers configured
+            {t('mcpServers.empty')}
           </div>
         )}
       </div>
 
       {/* Help Section */}
       <div className="bg-gray-100 dark:bg-gray-800/50 border border-gray-300 dark:border-gray-600 rounded-lg p-4">
-        <h4 className="font-medium text-gray-900 dark:text-gray-100 mb-2">About Codex MCP</h4>
+        <h4 className="font-medium text-gray-900 dark:text-gray-100 mb-2">{t('mcpServers.help.title')}</h4>
         <p className="text-sm text-gray-700 dark:text-gray-300">
-          Codex supports stdio-based MCP servers. You can add servers that extend Codex's capabilities
-          with additional tools and resources.
+          {t('mcpServers.help.description')}
         </p>
       </div>
     </div>