Improve product image handling and add costPerUnit

Added a utility to generate product image URLs, ensuring images are displayed correctly in the product table. Updated the Product model to include an optional costPerUnit field. Minor UI and code formatting improvements were made for consistency.

app/dashboard/products/page.tsx

@@ -45,7 +45,7 @@ const ProfitAnalysisModal = dynamic(() => import("@/components/modals/profit-ana
 
 function ProductTableSkeleton() {
   return (
-    <Card className="animate-in fade-in duration-500">
+    <Card className="animate-in fade-in duration-500 border-border/40 bg-background/50 backdrop-blur-sm shadow-sm">
       <CardHeader>
         <div className="flex items-center justify-between">
           <Skeleton className="h-6 w-32" />
@@ -60,8 +60,8 @@ function ProductTableSkeleton() {
           <div className="border-b p-4">
             <div className="flex items-center gap-4">
               {['Product', 'Category', 'Price', 'Stock', 'Status', 'Actions'].map((header, i) => (
-                <Skeleton 
-                  key={i} 
+                <Skeleton
+                  key={i}
                   className="h-4 w-20 flex-1 animate-in fade-in"
                   style={{
                     animationDelay: `${i * 50}ms`,
@@ -72,10 +72,10 @@ function ProductTableSkeleton() {
               ))}
             </div>
           </div>
-          
+
           {[...Array(8)].map((_, i) => (
-            <div 
-              key={i} 
+            <div
+              key={i}
               className="border-b last:border-b-0 p-4 animate-in fade-in"
               style={{
                 animationDelay: `${300 + i * 50}ms`,
@@ -152,7 +152,7 @@ export default function ProductsPage() {
   const [importModalOpen, setImportModalOpen] = useState(false);
   const [addProductOpen, setAddProductOpen] = useState(false);
   const [profitAnalysisOpen, setProfitAnalysisOpen] = useState(false);
-  const [selectedProductForAnalysis, setSelectedProductForAnalysis] = useState<{id: string, name: string} | null>(null);
+  const [selectedProductForAnalysis, setSelectedProductForAnalysis] = useState<{ id: string, name: string } | null>(null);
 
   // Fetch products and categories
   useEffect(() => {
@@ -169,7 +169,7 @@ export default function ProductsPage() {
     const fetchDataAsync = async () => {
       try {
         setLoading(true);
-        
+
         const [fetchedProducts, fetchedCategories] = await Promise.all([
           clientFetch('/products'),
           clientFetch('/categories'),
@@ -210,7 +210,7 @@ export default function ProductsPage() {
     }));
   };
 
-    // Handle input changes
+  // Handle input changes
   const handleChange = (
     e: ChangeEvent<HTMLInputElement | HTMLTextAreaElement>
   ) => setProductData({ ...productData, [e.target.name]: e.target.value });
@@ -226,7 +226,7 @@ export default function ProductsPage() {
     setProductData({ ...productData, pricing: updatedPricing });
   };
 
-  
+
   const handleSaveProduct = async (data: Product, file?: File | null) => {
     try {
       setLoading(true);
@@ -247,7 +247,7 @@ export default function ProductsPage() {
       // Save the product data
       const endpoint = editing ? `/products/${data._id}` : "/products";
       const method = editing ? "PUT" : "POST";
-      
+
       const productResponse = await clientFetch(endpoint, {
         method,
         headers: {
@@ -259,10 +259,10 @@ export default function ProductsPage() {
       // If there's a new image to upload
       if (file) {
         const imageEndpoint = `/products/${productResponse._id || data._id}/image`;
-        
+
         const formData = new FormData();
         formData.append("file", file);
-        
+
         await fetch(`${process.env.NEXT_PUBLIC_API_URL}${imageEndpoint}`, {
           method: "PUT",
           headers: {
@@ -279,10 +279,10 @@ export default function ProductsPage() {
       // Refresh products list
       const fetchedProducts = await clientFetch('/products');
       setProducts(fetchedProducts);
-      
+
       setModalOpen(false);
       setLoading(false);
-      
+
       toast.success(
         editing ? "Product updated successfully" : "Product added successfully"
       );
@@ -296,18 +296,18 @@ export default function ProductsPage() {
   // Handle delete product
   const handleDeleteProduct = async (productId: string) => {
     if (!confirm("Are you sure you want to delete this product?")) return;
-    
+
     try {
       setLoading(true);
-      
+
       await clientFetch(`/products/${productId}`, {
         method: "DELETE",
       });
-      
+
       // Refresh products list
       const fetchedProducts = await clientFetch('/products');
       setProducts(fetchedProducts);
-      
+
       toast.success("Product deleted successfully");
       setLoading(false);
     } catch (error) {
@@ -323,9 +323,9 @@ export default function ProductsPage() {
       ...product,
       pricing: product.pricing
         ? product.pricing.map((tier) => ({
-            minQuantity: tier.minQuantity,
-            pricePerUnit: tier.pricePerUnit,
-          }))
+          minQuantity: tier.minQuantity,
+          pricePerUnit: tier.pricePerUnit,
+        }))
         : [{ minQuantity: 1, pricePerUnit: 0 }],
       costPerUnit: product.costPerUnit || 0,
     });
@@ -343,16 +343,16 @@ export default function ProductsPage() {
       image: null, // Clear image so user can upload a new one
       pricing: product.pricing
         ? product.pricing.map((tier) => ({
-            minQuantity: tier.minQuantity,
-            pricePerUnit: tier.pricePerUnit,
-          }))
+          minQuantity: tier.minQuantity,
+          pricePerUnit: tier.pricePerUnit,
+        }))
         : [{ minQuantity: 1, pricePerUnit: 0 }],
       costPerUnit: product.costPerUnit || 0,
       // Reset stock to defaults for cloned product
       currentStock: 0,
       stockStatus: 'out_of_stock' as const,
     };
-    
+
     setProductData(clonedProduct);
     setEditing(false); // Set to false so it creates a new product
     setAddProductOpen(true);
@@ -390,19 +390,19 @@ export default function ProductsPage() {
   // Filter products based on search term
   const filteredProducts = products.filter(product => {
     if (!searchTerm) return true;
-    
+
     const searchLower = searchTerm.toLowerCase();
-    
+
     // Search in product name
     if (product.name.toLowerCase().includes(searchLower)) return true;
-    
+
     // Search in product description if it exists
     if (product.description && product.description.toLowerCase().includes(searchLower)) return true;
-    
+
     // Search in category name
     const categoryName = getCategoryNameById(product.category).toLowerCase();
     if (categoryName.includes(searchLower)) return true;
-    
+
     return false;
   });
 
@@ -437,19 +437,19 @@ export default function ProductsPage() {
   const handleToggleEnabled = async (productId: string, enabled: boolean) => {
     try {
       setLoading(true);
-      
+
       await clientFetch(`/products/${productId}`, {
         method: "PATCH",
         body: JSON.stringify({ enabled }),
       });
-      
+
       // Update the local state
-      setProducts(products.map(product => 
-        product._id === productId 
-          ? { ...product, enabled } 
+      setProducts(products.map(product =>
+        product._id === productId
+          ? { ...product, enabled }
           : product
       ));
-      
+
       toast.success(`Product ${enabled ? 'enabled' : 'disabled'} successfully`);
       setLoading(false);
     } catch (error) {
@@ -489,9 +489,9 @@ export default function ProductsPage() {
               )}
             </div>
             <div className="flex gap-2">
-              <Button 
-                onClick={() => setImportModalOpen(true)} 
-                variant="outline" 
+              <Button
+                onClick={() => setImportModalOpen(true)}
+                variant="outline"
                 className="gap-2 flex-1 sm:flex-none"
               >
                 <Upload className="h-4 w-4" />