feat(listings): implement Listings module with CRUD, media upload, and moderation

Full DDD/CQRS implementation for the Listings module (TEC-1423):
- Domain: Property, Listing, PropertyMedia entities with status machine
- Value Objects: Address, GeoPoint, Price with validation
- Events: ListingCreated, ListingApproved, ListingSold
- Commands: CreateListing, UpdateListingStatus, UploadMedia, ModerateListing
- Queries: GetListing, SearchListings, GetPendingModeration
- Infrastructure: Prisma repositories with PostGIS support, MinIO media storage
- Presentation: REST controller with JWT auth, role-based moderation
- 21 domain unit tests (all passing)

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

apps/api/src/modules/listings/index.ts

@@ -0,0 +1 @@
+export { ListingsModule } from './listings.module';