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/db.ts

@@ -0,0 +1,18 @@
+import { PrismaClient } from "@prisma/client";
+
+type PrismaGlobal = typeof globalThis & {
+  prisma?: PrismaClient;
+};
+
+const globalForPrisma = globalThis as PrismaGlobal;
+
+export const db =
+  globalForPrisma.prisma ??
+  new PrismaClient({
+    log:
+      process.env.NODE_ENV === "development" ? ["warn", "error"] : ["error"],
+  });
+
+if (process.env.NODE_ENV !== "production") {
+  globalForPrisma.prisma = db;
+}