feat(payments): add Order & Escrow entities with CQRS commands, Prisma schema

- Add Order entity with lifecycle (pending → paid → completed/cancelled/refunded)
- Add Escrow entity with hold/release/dispute flow for secure transactions
- Add PlatformFee value object with tiered commission calculation
- Implement CQRS: CreateOrder, CancelOrder, HoldEscrow, ReleaseEscrow commands
- Add GetOrderStatus query handler
- Add OrdersController with REST endpoints and DTOs
- Add Prisma models for Order, Escrow, EscrowStatusHistory
- Add domain event classes for order and escrow state changes
- Add unit tests for Order, Escrow entities and PlatformFee VO
- Update PROJECT_TRACKER to Wave 14 status

Co-Authored-By: Claude Opus 4 (1M context) <noreply@anthropic.com>

apps/api/src/modules/shared/domain/error-codes.ts

@@ -47,6 +47,15 @@ export enum ErrorCode {
   PAYMENT_ALREADY_PROCESSED = 'PAYMENT_ALREADY_PROCESSED',
   PAYMENT_INVALID_AMOUNT = 'PAYMENT_INVALID_AMOUNT',
 
+  // Order
+  ORDER_NOT_FOUND = 'ORDER_NOT_FOUND',
+  ORDER_INVALID_STATUS_TRANSITION = 'ORDER_INVALID_STATUS_TRANSITION',
+  ORDER_ALREADY_EXISTS = 'ORDER_ALREADY_EXISTS',
+
+  // Escrow
+  ESCROW_NOT_FOUND = 'ESCROW_NOT_FOUND',
+  ESCROW_INVALID_STATE = 'ESCROW_INVALID_STATE',
+
   // Subscription
   SUBSCRIPTION_NOT_FOUND = 'SUBSCRIPTION_NOT_FOUND',
   SUBSCRIPTION_ALREADY_ACTIVE = 'SUBSCRIPTION_ALREADY_ACTIVE',