fix build error

prisma/schema.prisma

@@ -168,7 +168,7 @@ model Credit {
   id            String    @id @default(cuid())
   userId        String
   amount        Float     // 交易金额（正数为充值，负数为消费）
-  balance       Float @default(0)    // 执行该交易后的余额
+  balance       Float @default(5)    // 执行该交易后的余额
   type          String    // "system_gift", "subscription_monthly", "user_purchase", "consumption"
   category      String?   // 消费类别: "simulation", "api_call", "export" 等
   note          String?   // 备注说明

src/app/api/credits/topup/route.ts

@@ -41,10 +41,7 @@ export async function POST(request: Request) {
         user.id,
         amount,
         'user_purchase',
-        'development',
-        null,
-        null,
-        `Development top-up: $${amount}`
+        `Development top-up: $${amount}`,
       )
 
       return NextResponse.json({