fix: Incorrect field reference (#2653)

Author: KATO-Hiro

src/lib/services/task_results.ts

@@ -261,8 +261,8 @@ function mergeTaskAndAnswer(
     taskResult.is_ac = status.is_ac;
     taskResult.user_id = userId;
 
-    if (status.updated_at) {
-      taskResult.updated_at = status.updated_at;
+    if (answer.updated_at) {
+      taskResult.updated_at = answer.updated_at;
     }
   }
 

src/lib/types/answer.ts

@@ -2,4 +2,5 @@ export interface TaskAnswer {
   task_id: string;
   user_id: string;
   status_id: string;
+  updated_at: Date;
 }