Refactor sales pipeline: ShopPO, Invoice, SysConfig models

Major refactor replacing Sale/Order with ShopPO → Invoice → LoadingSheet flow. Removed legacy Sale/Order models and features; introduced ShopPO, ShopPOItem, Invoice, LoadingSheetOrder, and SysConfig models. Updated related entities, enums, repositories, and controllers. Added new migrations for schema changes and system config. Overhauled business logic and DI registrations. Updated documentation with migration plan.

Distribution/Models/Enums.cs

@@ -3,15 +3,14 @@ namespace Distribution.Models
     public enum LocationType
     {  Warehouse, Vehicle, External }
 
-    public enum KycStatus { Pending,Verified, Rejected }
 
-    public enum MovementType { Sale, CustomerReturn, Transfer, Damage, Adjustment, Load, PurchaseReceipt, PurchaseReturn  }
+    public enum KycStatus { Pending, Verified, Rejected }
 
-    public enum LoadingSheetStatus {   Pending, DispatchConfirmed, ReceiptConfirmed, DiscrepancyFlagged, Resolved  }
+    public enum MovementType { Sale, CustomerReturn, Transfer, Damage, Adjustment, Load, PurchaseReceipt, PurchaseReturn }
 
-    public enum RideType { Delivery, Sale }
+    public enum LoadingSheetStatus { Planned, Confirmed }
 
-    public enum RideStatus { Draft, Open, Active, CancelRequested, Cancelled, Closed }
+    public enum RideStatus { Open, Cancelled, Closed }
 
     public enum CancelRequestType { VehicleBreakdown, DriverUnavailable, RouteIssue, Other }
 
@@ -19,16 +18,15 @@ namespace Distribution.Models
 
     public enum PurchaseOrderStatus { Issued, PartiallyReceived, Received, Closed, Cancelled }
 
-    public enum SaleStatus { Pending, Completed, Cancelled }
+    public enum ShopPOStatus { Pending, PartiallyFulfilled, Fulfilled, Cancelled }
 
-    public enum OrderStatus { Pending, PartiallyFulfilled, Fulfilled, Cancelled }
+    public enum InvoiceStatus { Draft, Printed, Finalized }
 
     public enum PaymentStatus { Pending, PartiallyPaid, Paid }
 
     public enum PaymentMethod { Cash, Credit }
 
-    public enum DeliveryTaskStatus
-    {   Pending, Delivered, PartiallyDelivered, Failed}
+    public enum DeliveryTaskStatus { Pending, Delivered, PartiallyDelivered, Failed }
 
     public enum ReturnMode { CreditDeduction, ItemExchange }
 
@@ -41,4 +39,10 @@ namespace Distribution.Models
     public enum SupplierClaimIssueType { Damaged, Short, Expired, WrongItem, Other }
 
     public enum SupplierClaimResolutionType { Replacement, Credit, Refund, PriceAdjustment }
+
+    /// <summary>
+    /// ModeA: Invoice auto-created when ShopPO is confirmed.
+    /// ModeB: Invoice created as a separate explicit step.
+    /// </summary>
+    public enum InvoiceCreationMode { ModeA, ModeB }
 }