feat: rename keep-notes to memento-note, migrate to PostgreSQL, fix MCP bugs

- Rename directory keep-notes -> memento-note with all code references
- Prisma: SQLite -> PostgreSQL (both app and MCP server schemas)
- Sync MCP schema with main app (add missing fields, relations, indexes)
- Delete 17 SQLite migrations (clean slate for PostgreSQL)
- Remove SQLite dependencies (@libsql/client, better-sqlite3, etc.)
- Fix MCP server: hardcoded Windows DB paths -> DATABASE_URL env var
- Fix MCP server: .dockerignore excluded index-sse.js (SSE mode broken)
- MCP Dockerfile: node:20 -> node:22
- Docker Compose: add postgres service, remove SQLite volume
- Generate favicon.ico, icon-192.png, icon-512.png, apple-icon.png
- Update layout.tsx icons and manifest.json for PNG icons
- Update all .env files for PostgreSQL
- Rewrite README.md with updated sections
- Remove mcp-server/node_modules and prisma/client-generated from git tracking

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

memento-note/components/settings/SettingsNav.tsx

@@ -0,0 +1,91 @@
+'use client'
+
+import Link from 'next/link'
+import { usePathname } from 'next/navigation'
+import { Settings, Sparkles, Palette, User, Database, Info, Check } from 'lucide-react'
+import { cn } from '@/lib/utils'
+import { useLanguage } from '@/lib/i18n'
+
+interface SettingsSection {
+  id: string
+  label: string
+  icon: React.ReactNode
+  href: string
+}
+
+interface SettingsNavProps {
+  className?: string
+}
+
+export function SettingsNav({ className }: SettingsNavProps) {
+  const pathname = usePathname()
+  const { t } = useLanguage()
+
+  const sections: SettingsSection[] = [
+    {
+      id: 'general',
+      label: t('generalSettings.title'),
+      icon: <Settings className="h-5 w-5" />,
+      href: '/settings/general'
+    },
+    {
+      id: 'ai',
+      label: t('aiSettings.title'),
+      icon: <Sparkles className="h-5 w-5" />,
+      href: '/settings/ai'
+    },
+    {
+      id: 'appearance',
+      label: t('appearance.title'),
+      icon: <Palette className="h-5 w-5" />,
+      href: '/settings/appearance'
+    },
+    {
+      id: 'profile',
+      label: t('profile.title'),
+      icon: <User className="h-5 w-5" />,
+      href: '/settings/profile'
+    },
+    {
+      id: 'data',
+      label: t('dataManagement.title'),
+      icon: <Database className="h-5 w-5" />,
+      href: '/settings/data'
+    },
+    {
+      id: 'about',
+      label: t('about.title'),
+      icon: <Info className="h-5 w-5" />,
+      href: '/settings/about'
+    }
+  ]
+
+  const isActive = (href: string) => pathname === href || pathname.startsWith(href + '/')
+
+  return (
+    <nav className={cn('space-y-1', className)}>
+      {sections.map((section) => (
+        <Link
+          key={section.id}
+          href={section.href}
+          className={cn(
+            'flex items-center gap-3 px-4 py-3 rounded-lg transition-colors',
+            'hover:bg-gray-100 dark:hover:bg-gray-800',
+            isActive(section.href)
+              ? 'bg-gray-100 dark:bg-gray-800 text-primary'
+              : 'text-gray-700 dark:text-gray-300'
+          )}
+        >
+          {isActive(section.href) && (
+            <Check className="h-4 w-4 text-primary" />
+          )}
+          {!isActive(section.href) && (
+            <div className="w-4" />
+          )}
+          {section.icon}
+          <span className="font-medium">{section.label}</span>
+        </Link>
+      ))}
+    </nav>
+  )
+}