refactor: Read and Update types to match their semantic purposes (#2627)

Author: KATO-Hiro

src/lib/types/contest_task_pair.ts

@@ -7,15 +7,15 @@ export type ContestTaskPair = ContestTaskPairOrigin;
 export type ContestTaskPairs = ContestTaskPair[];
 
 // For CRUD operation parameter types
+export type ContestTaskPairRead = ContestTaskPair;
+
 export type ContestTaskPairCreate = {
   contestId: string;
   taskTableIndex: string;
   taskId: string;
 };
 
-export type ContestTaskPairRead = ContestTaskPairCreate;
-
-export type ContestTaskPairUpdate = ContestTaskPairCreate;
+export type ContestTaskPairUpdate = Partial<ContestTaskPairCreate>;
 
 // For mapping and identification
 export type ContestTaskPairKey = `${string}:${string}`; // "contest_id:task_id"