feat: add sort_order to categories for controlling display order in the order wizard

shop/lib/actions/products.ts

@@ -20,7 +20,7 @@ export async function getCategories() {
   const { data, error } = await supabase
     .from('categories')
     .select('*')
-    .order('name', { ascending: true })
+    .order('sort_order', { ascending: true })
 
   if (error) throw error
   return data as Category[]

shop/lib/types.ts

@@ -16,6 +16,7 @@ export type Category = {
   name: string;
   description?: string | null;
   icon?: string | null;
+  sort_order: number;
   created_at: string;
 };