feat: rename 'fee' to 'unitPrice' across purchase components and models

- Updated form component to use 'unitPrice' instead of 'fee'.
- Adjusted product charge row form fields and templates to reflect the new naming.
- Modified receipt template and related components to utilize 'unitPrice'.
- Changed models and interfaces to replace 'fee' with 'unitPrice'.
- Updated supplier invoice and statistics components to align with the new naming convention.
- Added new API routes for dashboard and statistics modules.

src/app/modules/pos/store/index.ts

@@ -72,7 +72,7 @@ export class POSStore {
 
   readonly orderPricingInfo = computed(() => {
     const totalAmount = this.inOrderProducts().reduce(
-      (acc, curr) => acc + curr.fee * curr.count,
+      (acc, curr) => acc + curr.unitPrice * curr.count,
       0,
     );
     const taxAmount = totalAmount * 0.1;
@@ -188,7 +188,7 @@ export class POSStore {
             product,
             productId: product.id,
             count: 1,
-            fee: parseFloat(product.salePrice),
+            unitPrice: parseFloat(product.salePrice),
             maxQuantity: productStock.quantity,
           },
         ],
@@ -220,13 +220,13 @@ export class POSStore {
     }
   }
 
-  updateInOrderProductFee(productId: number, fee: number) {
+  updateInOrderProductFee(productId: number, unitPrice: number) {
     const inOrderProducts = this.state$().inOrderProducts;
 
     if (inOrderProducts.some((p) => p.productId === productId)) {
       const updatedProducts = inOrderProducts.map((p) => {
         if (p.productId === productId) {
-          return { ...p, fee: fee };
+          return { ...p, unitPrice: unitPrice };
         }
         return p;
       });
@@ -255,7 +255,7 @@ export class POSStore {
       items: this.inOrderProducts()?.map((item) => ({
         productId: item.productId,
         count: item.count,
-        fee: item.fee,
+        unitPrice: item.unitPrice,
       })),
     };
     this.service.submitOrder(this.posId, orderPayload).subscribe();