feat: add authentication and user management features

- Implemented AuthButton component for Discord sign-in and sign-out functionality.
- Created CopyButton component for copying server IP addresses.
- Developed EventCard and GradeCard components for displaying events and grades.
- Added Footer and Navbar components for site navigation and information.
- Introduced PurchaseButton for handling grade purchases with Stripe integration.
- Created SectionHeader component for consistent section titles.
- Implemented session management with SessionProvider for NextAuth.
- Set up PostgreSQL database with Docker and Prisma for data management.
- Added admin guard functionality to restrict access to certain routes.
- Configured NextAuth with Discord provider for user authentication.
- Defined Prisma schema for user, admin, grade, event, and purchase models.
- Seeded database with initial grades and events data.
- Added SVG hero image for the landing page.
- Extended NextAuth types to include additional user properties.

components/section-header.tsx

@@ -0,0 +1,25 @@
+type SectionHeaderProps = {
+  eyebrow: string;
+  title: string;
+  description?: string;
+};
+
+export default function SectionHeader({
+  eyebrow,
+  title,
+  description,
+}: SectionHeaderProps) {
+  return (
+    <div className="mx-auto mb-10 max-w-2xl text-center">
+      <p className="text-xs uppercase tracking-[0.4em] text-cyan-200/80">
+        {eyebrow}
+      </p>
+      <h2 className="mt-4 text-3xl font-semibold text-white md:text-4xl">
+        {title}
+      </h2>
+      {description ? (
+        <p className="mt-3 text-sm text-slate-300">{description}</p>
+      ) : null}
+    </div>
+  );
+}