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/app/AppShell.tsx

@@ -8,7 +8,8 @@
  */
 
 import type { ReactNode } from 'react'
-import { PanelLeft } from 'lucide-react'
+import { useTranslation } from 'react-i18next'
+import { ChevronsRight } from 'lucide-react'
 import Sidebar from '../components/layout/Sidebar'
 import TabBar from '../components/layout/TabBar'
 import TabContent from '../components/layout/TabContent'
@@ -24,8 +25,10 @@ export interface AppShellProps {
   onToggleSidebar: () => void
   onToggleMobileSidebar: () => void
   onCloseMobileSidebar: () => void
-  onNewSession: () => void
+  onNewSession: (group?: string) => void
   onQuickConnect: () => void
+  onRdpConnect?: () => void
+  onVncConnect?: () => void
   onOpenLauncher: () => void
   onEditSession: (session: Session) => void
   children?: ReactNode
@@ -42,21 +45,20 @@ function TitleBar() {
       className="bg-dark-900/95 flex h-10 flex-shrink-0 select-none items-center border-b border-dark-800"
     >
       <div data-tauri-drag-region className="h-full w-[78px] flex-shrink-0" aria-hidden />
-      <div data-tauri-drag-region className="flex h-full min-w-0 flex-1 items-center justify-center px-2">
-        <span className="pointer-events-none truncate text-[11px] tracking-wide text-txt-faint">OpsXShell</span>
-      </div>
+      <div data-tauri-drag-region className="flex h-full min-w-0 flex-1 items-center justify-center px-2" />
       <div data-tauri-drag-region className="h-full w-[78px] flex-shrink-0" aria-hidden />
     </header>
   )
 }
 
 function MobileMenuButton({ onClick }: { onClick: () => void }) {
+  const { t } = useTranslation('common')
   return (
     <button
       type="button"
       onClick={onClick}
       className="titlebar-no-drag flex h-10 w-10 items-center justify-center text-txt-muted transition-colors hover:bg-dark-800 hover:text-content-primary"
-      aria-label="切换侧边栏"
+      aria-label={t('sidebar.toggle')}
     >
       <svg className="h-5 w-5" fill="none" stroke="currentColor" viewBox="0 0 24 24" aria-hidden>
         <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 6h16M4 12h16M4 18h16" />
@@ -66,15 +68,16 @@ function MobileMenuButton({ onClick }: { onClick: () => void }) {
 }
 
 function ExpandSidebarButton({ onClick }: { onClick: () => void }) {
+  const { t } = useTranslation('common')
   return (
     <button
       type="button"
       onClick={onClick}
-      className="titlebar-no-drag flex h-10 w-10 flex-shrink-0 items-center justify-center border-r border-dark-700/40 text-txt-muted transition-colors hover:bg-dark-700/60 hover:text-content-primary"
-      title="展开侧栏 (Ctrl/Cmd+B)"
-      aria-label="展开侧栏"
+      className="titlebar-no-drag group flex h-10 w-9 flex-shrink-0 items-center justify-center border-r border-dark-700/30 text-txt-faint transition-colors hover:bg-dark-700/50 hover:text-txt-muted"
+      title={t('sidebar.expand')}
+      aria-label={t('sidebar.expandAria')}
     >
-      <PanelLeft className="h-4 w-4" />
+      <ChevronsRight className="h-3.5 w-3.5 opacity-70 transition-opacity group-hover:opacity-100" strokeWidth={1.75} />
     </button>
   )
 }
@@ -89,12 +92,14 @@ export default function AppShell({
   onCloseMobileSidebar,
   onNewSession,
   onQuickConnect,
+  onRdpConnect,
+  onVncConnect,
   onOpenLauncher,
   onEditSession,
   children,
 }: AppShellProps) {
-  const handleSidebarNewSession = () => {
-    onNewSession()
+  const handleSidebarNewSession = (group?: string) => {
+    onNewSession(group)
     if (isMobile) onCloseMobileSidebar()
   }
 
@@ -151,7 +156,13 @@ export default function AppShell({
           </div>
 
           <div className="titlebar-no-drag min-h-0 flex-1 overflow-hidden">
-            <TabContent activeTabId={activeTabId} onNewSession={onNewSession} onQuickConnect={onQuickConnect} />
+            <TabContent
+              activeTabId={activeTabId}
+              onNewSession={onNewSession}
+              onQuickConnect={onQuickConnect}
+              onRdpConnect={onRdpConnect}
+              onVncConnect={onVncConnect}
+            />
           </div>
         </main>
       </div>