feat: initial commit — backend API + student cabinet frontend

- Go backend: auth (JWT), points earn/spend, QR token generation,
  partners, admin grant/stats endpoints with chi router
- Next.js 14 frontend: login, student dashboard, transaction history,
  QR display, partners list
- PostgreSQL migrations (4 tables), Redis cache, Docker Compose
- CORS middleware, role-based route protection, Zustand auth store

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/components/ui/Card.tsx

@@ -0,0 +1,16 @@
+import { type HTMLAttributes } from 'react';
+
+interface CardProps extends HTMLAttributes<HTMLDivElement> {
+  children: React.ReactNode;
+}
+
+export function Card({ children, className = '', ...props }: CardProps) {
+  return (
+    <div
+      className={`rounded-2xl bg-gray-800 p-6 shadow-sm ring-1 ring-gray-700 ${className}`}
+      {...props}
+    >
+      {children}
+    </div>
+  );
+}