getCookie 제거

backend/api/dashboard/stats.get.ts

@@ -1,4 +1,5 @@
 import { query } from '../../utils/db'
+import { requireAuth } from '../../utils/session'
 
 /**
  * 대시보드 통계 API
@@ -9,10 +10,7 @@ import { query } from '../../utils/db'
  * - 제출 현황
  */
 export default defineEventHandler(async (event) => {
-  const userId = getCookie(event, 'user_id')
-  if (!userId) {
-    throw createError({ statusCode: 401, message: '로그인이 필요합니다.' })
-  }
+  const userId = await requireAuth(event)
   
   const q = getQuery(event)
   const year = parseInt(q.year as string) || new Date().getFullYear()