fix(deploy): tag rollback images before pull, prune after smoke test

Previously, `docker image prune` ran immediately after deploying new
containers, potentially deleting the old images needed for rollback
if smoke tests subsequently failed. Now the deploy pipeline:

1. Tags current images as :rollback before pulling new versions
2. Only runs `docker image prune` after smoke tests pass
3. Uses explicit :rollback tags for rollback instead of relying on
   Docker layer cache (which is fragile)

Applied to:
- scripts/deploy-production.sh (manual deploy script)
- .github/workflows/deploy.yml (staging + production CI jobs)
- docs/deployment.md (updated rollback documentation)

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/listings/domain/events/listing-updated.event.ts

@@ -0,0 +1,16 @@
+import type { ListingStatus } from '@prisma/client';
+import type { DomainEvent } from '@modules/shared';
+
+export class ListingUpdatedEvent implements DomainEvent {
+  readonly eventName = 'listing.updated';
+  readonly occurredAt = new Date();
+
+  constructor(
+    public readonly aggregateId: string,
+    public readonly propertyId: string,
+    public readonly sellerId: string,
+    public readonly previousStatus: ListingStatus,
+    public readonly newStatus: ListingStatus,
+    public readonly updatedFields: string[],
+  ) {}
+}