perf(webapp): Add BatchTaskRun index to speed up the batch list dashboard page (#2499)

internal-packages/database/prisma/migrations/20250912155941_add_batch_task_run_dashboard_index/migration.sql

@@ -0,0 +1,2 @@
+-- CreateIndex
+CREATE INDEX CONCURRENTLY IF NOT EXISTS "BatchTaskRun_runtimeEnvironmentId_id_idx" ON "public"."BatchTaskRun"("runtimeEnvironmentId", "id" DESC);

internal-packages/database/prisma/schema.prisma

@@ -1578,6 +1578,8 @@ model BatchTaskRun {
   ///this is used for all engine versions
   @@unique([runtimeEnvironmentId, idempotencyKey])
   @@index([dependentTaskAttemptId])
+  // This is for the batch list dashboard page
+  @@index([runtimeEnvironmentId, id(sort: Desc)])
 }
 
 enum BatchTaskRunStatus {