feat: add supplier payment and allocation models, API, and frontend components

- Created `SupplierPayment` and `SupplierPaymentGRN` models for managing supplier payments and their allocations.
- Implemented API endpoints for listing and creating supplier payments.
- Developed frontend components for displaying and recording supplier payments, including a dialog for payment creation.
- Integrated GRN allocations into the payment creation process, ensuring total allocations match the payment amount.
- Added pagination and loading states for the payments list.

Distribution/Features/SupplierPayment/SupplierPaymentDTOs.cs

@@ -0,0 +1,43 @@
+using Distribution.Models;
+
+namespace Distribution.Features.SupplierPayment;
+
+public record SupplierPaymentAllocationRequest(
+    Guid GoodsReceiptId,
+    decimal AllocatedAmount);
+
+public record CreateSupplierPaymentRequest(
+    decimal Amount,
+    PaymentMethod Method,
+    // One or more GRNs this payment covers. Sum of AllocatedAmount must equal Amount.
+    List<SupplierPaymentAllocationRequest> Allocations,
+    // Cash: required.
+    Guid? BankAccountId = null,
+    // Cheque: required — an Unused page from an Active cheque book.
+    Guid? ChequePageId = null,
+    string? Notes = null,
+    Guid? PaidByUserId = null);
+
+public record SupplierPaymentAllocationResponse(
+    Guid GoodsReceiptId,
+    decimal AllocatedAmount);
+
+public record SupplierPaymentResponse(
+    Guid Id,
+    Guid SupplierId,
+    decimal Amount,
+    PaymentMethod Method,
+    Guid? BankAccountId,
+    Guid? ChequePageId,
+    string? ChequeNo,
+    DateTime PaidAt,
+    Guid? PaidByUserId,
+    string? Notes,
+    List<SupplierPaymentAllocationResponse> Allocations,
+    DateTime CreatedAt);
+
+public record PagedSupplierPaymentsResponse(
+    List<SupplierPaymentResponse> Items,
+    int Page,
+    int PageSize,
+    int Total);