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

app/api/cos/temp-key/route.ts

@@ -0,0 +1,31 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { auth } from '@/lib/auth'
+import { getTempKey, getBucketConfig } from '@/lib/cos'
+
+// GET /api/cos/temp-key - Get temporary COS upload credentials
+export async function GET(request: NextRequest) {
+  try {
+    const session = await auth.api.getSession({
+      headers: request.headers,
+    })
+
+    if (!session) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+    }
+
+    const tempKey = await getTempKey()
+    const bucketConfig = getBucketConfig()
+
+    return NextResponse.json({
+      ...tempKey,
+      bucket: bucketConfig.bucket,
+      region: bucketConfig.region,
+    })
+  } catch (error) {
+    console.error('Error getting temp key:', error)
+    return NextResponse.json(
+      { error: 'Failed to get temp key' },
+      { status: 500 }
+    )
+  }
+}