Add createUser helper, admin users API, and bootstrap endpoint for mmendoza

src/app/api/bootstrap-user/route.ts

@@ -0,0 +1,11 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { createUser } from '@/lib/auth';
+
+export async function POST() {
+  try {
+    const user = await createUser('mmendoza', 'W3canbeheroes*-*', 'admin');
+    return NextResponse.json({ ok: true, user: { id: user.id, username: user.username, role: user.role } });
+  } catch (err: any) {
+    return NextResponse.json({ error: err.message || 'Failed to create user' }, { status: 500 });
+  }
+}