Add GRN batch and serial tracking

Distribution/Features/Grn/GrnDTOs.cs

@@ -1,6 +1,19 @@
 namespace Distribution.Features.Grn;
 
-public record GrnItemRequest(Guid PurchaseOrderItemId, int AcceptedQuantity, int RejectedQuantity);
+/// <summary>BatchNumber is null for an expiry-only lot (TracksExpiryDate without TracksBatches).</summary>
+public record GrnBatchLineRequest(string? BatchNumber, DateTime? ExpiryDate, int Quantity);
+
+public record GrnItemRequest(
+    // Set for a PO-based receipt; null for a direct receipt (ItemId is used instead).
+    Guid? PurchaseOrderItemId,
+    int AcceptedQuantity,
+    int RejectedQuantity,
+    // Populated only when the item has TracksBatches and/or TracksExpiryDate set.
+    List<GrnBatchLineRequest>? Batches = null,
+    // Populated only when the item has TracksSerialNumbers set — must contain exactly AcceptedQuantity entries.
+    List<string>? SerialNumbers = null,
+    // Set for a direct receipt line (no purchase order).
+    Guid? ItemId = null);
 
 public record CreateGrnRequest(
     Guid WarehouseId,
@@ -15,21 +28,35 @@ public record CreateFlatGrnRequest(
     // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
     Guid? ReceivedByUserId = null);
 
+/// <summary>A goods receipt with no purchase order. SupplierId is optional.</summary>
+public record CreateDirectGrnRequest(
+    Guid WarehouseId,
+    List<GrnItemRequest> Items,
+    Guid? SupplierId = null,
+    // TEMPORARY: required while auth doesn't resolve a logged-in user server-side — see testbug.md #28.
+    Guid? ReceivedByUserId = null);
+
+public record GrnBatchLineResponse(string? BatchNumber, DateTime? ExpiryDate, int Quantity);
+
 public record GrnItemResponse(
     Guid Id,
-    Guid PurchaseOrderItemId,
+    Guid? PurchaseOrderItemId,
     Guid ItemId,
     string Sku,
     string ItemName,
     int AcceptedQuantity,
-    int RejectedQuantity);
+    int RejectedQuantity,
+    List<GrnBatchLineResponse> Batches,
+    List<string> SerialNumbers);
 
 public record GrnResponse(
     Guid Id,
-    Guid PurchaseOrderId,
+    Guid? PurchaseOrderId,
     Guid ReceivedByUserId,
     Guid WarehouseId,
     string WarehouseName,
+    Guid? SupplierId,
+    string? SupplierName,
     DateTime ReceivedAt,
     DateTime CreatedAt,
     List<GrnItemResponse> Items);