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.

lib/format.ts

@@ -0,0 +1,14 @@
+export const formatEventDate = (value: Date) => {
+  return new Intl.DateTimeFormat("en-GB", {
+    dateStyle: "medium",
+    timeStyle: "short",
+  }).format(value);
+};
+
+export const formatPrice = (value: number) => {
+  return new Intl.NumberFormat("en-GB", {
+    style: "currency",
+    currency: "EUR",
+    maximumFractionDigits: 0,
+  }).format(value);
+};