feat: RTL/i18n, AI translate+undo, no-refresh saves, settings perf

- RTL: force dir=rtl on LabelFilter, NotesViewToggle, LabelManagementDialog
- i18n: add missing keys (notifications, privacy, edit/preview, AI translate/undo)
- Settings pages: convert to Server Components (general, appearance) + loading skeleton
- AI menu: add Translate option (10 languages) + Undo AI button in toolbar
- Fix: saveInline uses REST API instead of Server Action → eliminates all implicit refreshes in list mode
- Fix: NotesTabsView notes sync effect preserves selected note on content changes
- Fix: auto-tag suggestions now filter already-assigned labels
- Fix: color change in card view uses local state (no refresh)
- Fix: nav links use <Link> for prefetching (Settings, Admin)
- Fix: suppress duplicate label suggestions already on note
- Route: add /api/ai/translate endpoint

keep-notes/components/settings/SettingsNav.tsx

@@ -2,7 +2,7 @@
 
 import Link from 'next/link'
 import { usePathname } from 'next/navigation'
-import { Settings, Sparkles, Palette, User, Database, Info, Check } from 'lucide-react'
+import { Settings, Sparkles, Palette, User, Database, Info, Check, Key } from 'lucide-react'
 import { cn } from '@/lib/utils'
 import { useLanguage } from '@/lib/i18n'
 
@@ -52,6 +52,12 @@ export function SettingsNav({ className }: SettingsNavProps) {
       icon: <Database className="h-5 w-5" />,
       href: '/settings/data'
     },
+    {
+      id: 'mcp',
+      label: t('mcpSettings.title'),
+      icon: <Key className="h-5 w-5" />,
+      href: '/settings/mcp'
+    },
     {
       id: 'about',
       label: t('about.title'),