- Replace Dapper/Npgsql direct DB access with HttpClient proxy to microservice APIs
- Create BffHttpClient.cs with AuthForwardingHandler (forwards JWT tokens)
- Register 9 named HttpClients: Merchant, Catalog, Order, Inventory, Membership, Wallet, Promotion, Booking, FnbEngine
- Delete BffDbConnectionFactory.cs and TenantContext.cs (no more direct DB)
- Remove Dapper and Npgsql package references from .csproj
- All 10 controllers are now thin HTTP proxy bridges
- Zero breaking changes: all api/bff/ routes preserved