docs: Update plan (#2734)

Author: KATO-Hiro

docs/dev-notes/2025-10-22/add-contest-task-pairs-to-seeds/plan.md

@@ -89,16 +89,30 @@ async function addContestTaskPairs() {
   for (const pair of contest_task_pairs) {
     contestTaskPairQueue.add(async () => {
       try {
-        const registeredPair = await prisma.contestTaskPair.findUnique({
-          where: {
-            contest_id_task_id: {
-              contest_id: pair.contest_id,
-              task_id: pair.task_id,
+        const [registeredPair, registeredTask] = await Promise.all([
+          prisma.contestTaskPair.findUnique({
+            where: {
+              contestId_taskId: {
+                contestId: pair.contest_id,
+                taskId: pair.problem_id,
+              },
             },
-          },
-        });
-
-        if (!registeredPair) {
+          }),
+          prisma.task.findUnique({
+            where: { task_id: pair.problem_id },
+          }),
+        ]);
+
+        if (!registeredTask) {
+          console.warn(
+            'Skipped contest task pair due to missing task:',
+            pair.problem_id,
+            'for contest',
+            pair.contest_id,
+            'index',
+            pair.problem_index,
+          );
+        } else if (!registeredPair) {
           await addContestTaskPair(pair, contestTaskPairFactory);
           console.log(
             'contest_id:',