refactor: rewrite ke codebase lama

prisma/migrations/20260112094610_add_relation_batch_and_lamaran/migration.sql

@@ -0,0 +1,5 @@
+-- CreateIndex
+CREATE INDEX `lamaran_magang_batch_idx` ON `lamaran_magang`(`batch`);
+
+-- AddForeignKey
+ALTER TABLE `lamaran_magang` ADD CONSTRAINT `lamaran_magang_batch_foreign` FOREIGN KEY (`batch`) REFERENCES `batch`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;