Add FlatPaymentController with RESTful payment endpoints

Introduced FlatPaymentController under Distribution.Features.Payment, providing GET and POST endpoints at /api/payments. Supports listing, retrieving, and creating payments with filtering and error handling. Business logic is delegated to PaymentService.

Distribution/Features/Payment/PaymentService.cs

@@ -1,4 +1,5 @@
 using Distribution.Features.Sale;
+using Distribution.Features.Stock;
 using Distribution.Infra.Authorization;
 using Distribution.Infra.UoW;
 using Distribution.Models;
@@ -14,6 +15,19 @@ public class PaymentService(
     private static PaymentResponse ToResponse(Models.Payment p) =>
         new(p.Id, p.FK_SaleId, p.FK_StoreId, p.Amount, p.Method, p.CollectedAt, p.CollectedBy, p.CreatedAt);
 
+    public async Task<PagedResponse<PaymentResponse>> GetAllAsync(Guid? storeId, Guid? saleId, int page, int pageSize)
+    {
+        var total = await repo.GetCountAsync(storeId, saleId);
+        var items = await repo.GetAllAsync(storeId, saleId, page, pageSize);
+        return new PagedResponse<PaymentResponse>(page, pageSize, total, items.Select(ToResponse).ToList());
+    }
+
+    public async Task<PaymentResponse?> GetByIdAsync(Guid id)
+    {
+        var payment = await repo.GetByIdAsync(id);
+        return payment is null ? null : ToResponse(payment);
+    }
+
     public async Task<List<PaymentResponse>?> GetBySaleIdAsync(Guid saleId)
     {
         var sale = await saleRepo.GetByIdAsync(saleId);