chore(plan): fix stale src/db doc refs + register s3-routing test

- 8 repository/port doc comments pointed at long-gone src/db/*
  layout; now reference the real drizzle repository paths
- test:unit and test:s3 now include test/s3-routing.test.ts
  (was passing but never wired into any script)

src/domain/ports/bucket-repository.ts

@@ -3,7 +3,7 @@ import type { Bucket } from '../entities/bucket';
 /**
  * Repository interface for Bucket entity persistence.
  *
- * Abstracts the bucket CRUD operations currently in `src/db/buckets.ts`.
+ * Abstracts the bucket CRUD operations currently in `infrastructure/persistence/repositories/bucket-repository.ts`.
  */
 export interface IBucketRepository {
   /**