chore: FeatureFlag add createdAt and updatedAt (#2880)

It’s useful to know when they were modified for debugging and auditing.

For existing rows createdAt and updatedAt are set to now() during the
migration, to avoid a nullable column.

Author: matt-aitken

internal-packages/database/prisma/migrations/20260113182122_add_timestamps_to_feature_flag/migration.sql

@@ -0,0 +1,4 @@
+-- AlterTable
+ALTER TABLE "public"."FeatureFlag" ADD COLUMN     "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+ADD COLUMN     "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP;
+

internal-packages/database/prisma/schema.prisma

@@ -1144,6 +1144,9 @@ model FeatureFlag {
 
   key   String @unique
   value Json?
+
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
 }
 
 model WorkerInstance {