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/admin-sidebar.tsx

@@ -0,0 +1,75 @@
+'use client'
+
+import Link from 'next/link'
+import { usePathname } from 'next/navigation'
+import { LayoutDashboard, Users, Brain, Settings } from 'lucide-react'
+import { cn } from '@/lib/utils'
+
+export interface AdminSidebarProps {
+  className?: string
+}
+
+export interface NavItem {
+  title: string
+  href: string
+  icon: React.ReactNode
+}
+
+const navItems: NavItem[] = [
+  {
+    title: 'Dashboard',
+    href: '/admin',
+    icon: <LayoutDashboard className="h-5 w-5" />,
+  },
+  {
+    title: 'Users',
+    href: '/admin/users',
+    icon: <Users className="h-5 w-5" />,
+  },
+  {
+    title: 'AI Management',
+    href: '/admin/ai',
+    icon: <Brain className="h-5 w-5" />,
+  },
+  {
+    title: 'Settings',
+    href: '/admin/settings',
+    icon: <Settings className="h-5 w-5" />,
+  },
+]
+
+export function AdminSidebar({ className }: AdminSidebarProps) {
+  const pathname = usePathname()
+
+  return (
+    <aside
+      className={cn(
+        'w-64 bg-white dark:bg-zinc-900 border-r border-gray-200 dark:border-gray-800 p-4',
+        className
+      )}
+    >
+      <nav className="space-y-1">
+        {navItems.map((item) => {
+          const isActive = pathname === item.href || (item.href !== '/admin' && pathname?.startsWith(item.href))
+          
+          return (
+            <Link
+              key={item.href}
+              href={item.href}
+              className={cn(
+                'flex items-center gap-3 px-4 py-3 rounded-lg text-sm font-medium transition-colors',
+                'hover:bg-gray-100 dark:hover:bg-zinc-800',
+                isActive
+                  ? 'bg-gray-100 dark:bg-zinc-800 text-gray-900 dark:text-white font-semibold'
+                  : 'text-gray-600 dark:text-gray-400'
+              )}
+            >
+              {item.icon}
+              <span>{item.title}</span>
+            </Link>
+          )
+        })}
+      </nav>
+    </aside>
+  )
+}