feat(i18n): add multi-language support (ja/ko/vi/ru/zh-TW) with system auto-detection

- Extend AppLanguage to 7 locales: zh-CN, zh-TW, en, ja, ko, vi, ru
- Auto-detect system language via navigator.languages; fallback to English
- Add BCP47 locale mapping for date formatting and sorting
- Create 50 translation JSON files (5 languages × 10 namespaces, 1137 keys each)
- Update language selector with native language names
- Extend locale key parity test to cover all 7 languages (70 assertions)
- Add VNC/RDP desktop, serial terminal, AI agent, port forwarding, and SFTP features
- Add credential encryption, host metrics, session backup crypto, and zmodem bridge
- Update Rust backend: desktop services, host metrics, SSH/SFTP enhancements

src/components/sessions/QuickConnectDialog.tsx

@@ -4,10 +4,12 @@
  */
 
 import { useEffect, useState } from 'react'
-import { Zap, ArrowRight, AlertCircle } from 'lucide-react'
+import { useTranslation } from 'react-i18next'
+import { LogIn, ArrowRight, AlertCircle } from 'lucide-react'
 import { useTabStore } from '../../stores/tabStore'
 import Modal from '../common/Modal'
 import Button from '../common/Button'
+import { translateErrorMessage } from '../../i18n/format'
 
 interface QuickConnectDialogProps {
   isOpen: boolean
@@ -62,6 +64,7 @@ export function parseSshTarget(raw: string): {
 }
 
 export default function QuickConnectDialog({ isOpen, onClose, initialTarget = '' }: QuickConnectDialogProps) {
+  const { t } = useTranslation(['sessions', 'common'])
   const { addTab } = useTabStore()
   const [target, setTarget] = useState('')
   const [password, setPassword] = useState('')
@@ -79,7 +82,7 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
   const handleSubmit = async () => {
     const parsed = parseSshTarget(target)
     if (!parsed) {
-      setError('请输入主机，例如 root@192.168.1.10 或 opsbase.cn:5555')
+      setError(t('sessions:quickConnect.errorInvalidTarget'))
       return
     }
     setIsConnecting(true)
@@ -101,7 +104,8 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
       setTarget('')
       setPassword('')
     } catch (err: unknown) {
-      setError((err instanceof Error ? err.message : String(err)) || '连接失败')
+      const raw = (err instanceof Error ? err.message : String(err)) || t('sessions:quickConnect.errorConnectFailed')
+      setError(translateErrorMessage(raw))
     } finally {
       setIsConnecting(false)
     }
@@ -111,8 +115,8 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
     <Modal
       isOpen={isOpen}
       onClose={onClose}
-      title="快速连接"
-      icon={<Zap className="h-5 w-5" />}
+      title={t('sessions:quickConnect.title')}
+      icon={<LogIn className="h-5 w-5" />}
       size="md"
       showFooter={false}
     >
@@ -124,24 +128,25 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
         className="space-y-4"
       >
         <div>
-          <label className="ui-label">目标</label>
+          <label className="ui-label">{t('sessions:quickConnect.target')}</label>
           <input
             type="text"
             required
             autoFocus
             value={target}
             onChange={(e) => setTarget(e.target.value)}
-            placeholder="root@192.168.1.10:22"
+            placeholder={t('sessions:quickConnect.targetPlaceholder')}
             className="ui-input font-mono"
             autoComplete="off"
             spellCheck={false}
           />
-          <p className="mt-1.5 text-[11px] leading-relaxed text-txt-faint">支持 host、user@host、user@host:port</p>
+          <p className="mt-1.5 text-[11px] leading-relaxed text-txt-faint">{t('sessions:quickConnect.targetHint')}</p>
         </div>
 
         <div>
           <label className="ui-label">
-            密码 <span className="font-normal text-txt-faint">可选 · 用密钥可留空</span>
+            {t('sessions:quickConnect.password')}{' '}
+            <span className="font-normal text-txt-faint">{t('sessions:quickConnect.passwordOptional')}</span>
           </label>
           <input
             type="password"
@@ -162,7 +167,7 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
 
         <div className="border-dark-700/50 flex justify-end gap-2.5 border-t pt-2">
           <Button type="button" variant="ghost" size="sm" onClick={onClose} disabled={isConnecting}>
-            取消
+            {t('common:action.cancel')}
           </Button>
           <Button
             type="submit"
@@ -171,7 +176,7 @@ export default function QuickConnectDialog({ isOpen, onClose, initialTarget = ''
             loading={isConnecting}
             icon={<ArrowRight className="h-3.5 w-3.5" />}
           >
-            连接
+            {t('sessions:quickConnect.connect')}
           </Button>
         </div>
       </form>