feat: alphabet list, change Layout etc

lib/views/widgets/product_tile.dart

@@ -26,10 +26,8 @@ class ProductTile extends StatelessWidget {
     final scheme = theme.colorScheme;
     final l10n = AppLocalizations.of(context);
 
-    final outOfStock = product.stockQuantity <= 0;
-    final lowStock =
-        product.stockQuantity > 0 &&
-        product.stockQuantity <= product.lowStockThreshold;
+    final outOfStock = product.isOutOfStock;
+    final lowStock = !outOfStock && product.isLowStock;
 
     final hasImage = product.imagePath != null && product.imagePath!.isNotEmpty;
 
@@ -142,11 +140,11 @@ class _StockBadge extends StatelessWidget {
   Widget build(BuildContext context) {
     final scheme = Theme.of(context).colorScheme;
 
-    if (product.stockQuantity <= 0) {
+    if (product.isOutOfStock) {
       return const SizedBox.shrink();
     }
 
-    final low = product.stockQuantity <= product.lowStockThreshold;
+    final low = product.isLowStock;
 
     return Container(
       padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
@@ -157,7 +155,7 @@ class _StockBadge extends StatelessWidget {
         borderRadius: BorderRadius.circular(999),
       ),
       child: Text(
-        '${product.stockQuantity}',
+        product.infiniteStock ? '∞' : '${product.stockQuantity}',
         style: TextStyle(
           fontSize: 12,
           fontWeight: FontWeight.w800,