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/app/(auth)/register/page.tsx

@@ -0,0 +1,20 @@
+import { RegisterForm } from '@/components/register-form';
+import { getSystemConfig } from '@/lib/config';
+import { redirect } from 'next/navigation';
+ 
+export default async function RegisterPage() {
+  const config = await getSystemConfig();
+  const allowRegister = config.ALLOW_REGISTRATION !== 'false' && process.env.ALLOW_REGISTRATION !== 'false';
+
+  if (!allowRegister) {
+    redirect('/login');
+  }
+
+  return (
+    <main className="flex items-center justify-center md:h-screen">
+      <div className="relative mx-auto flex w-full max-w-[400px] flex-col space-y-2.5 p-4 md:-mt-32">
+        <RegisterForm />
+      </div>
+    </main>
+  );
+}