feat: initial project setup for Meme Studio

Next.js 14 App Router application for managing homophone pun game levels:

- Better Auth with Prisma adapter for authentication
- MySQL database with Prisma ORM
- Level CRUD operations with drag-and-drop reordering
- Tencent COS integration for image uploads
- shadcn/ui components with Tailwind CSS
- TanStack Query for server state management

lib/auth.ts

@@ -0,0 +1,20 @@
+import { betterAuth } from 'better-auth'
+import { prismaAdapter } from 'better-auth/adapters/prisma'
+import { prisma } from './prisma'
+
+export const auth = betterAuth({
+  database: prismaAdapter(prisma, {
+    provider: 'mysql',
+  }),
+  emailAndPassword: {
+    enabled: true,
+  },
+  trustedOrigins: [process.env.BETTER_AUTH_URL || 'http://localhost:3000'],
+  secret: process.env.BETTER_AUTH_SECRET,
+  session: {
+    expiresIn: 60 * 60 * 24 * 7, // 7 days
+    updateAge: 60 * 60 * 24, // 1 day
+  },
+})
+
+export type Auth = typeof auth