Add grid layout for catalog cards + hover shadow

- CatalogPage: added gridColumns prop (1/2/3 columns)
- Card: added hover:shadow-lg on interactive cards
- Products, hubs, suppliers pages now use 3-column grid
- Offers remain full-width (gridColumns=1 default)

app/components/page/CatalogPage.vue

@@ -40,7 +40,7 @@
               <slot name="header" />
               <slot name="filters" />
 
-              <Stack gap="3">
+              <div :class="gridClass">
                 <div
                   v-for="item in displayItems"
                   :key="item.uuid"
@@ -51,7 +51,7 @@
                 >
                   <slot name="card" :item="item" />
                 </div>
-              </Stack>
+              </div>
 
               <slot name="pagination" />
 
@@ -96,7 +96,7 @@
               <slot name="header" />
               <slot name="filters" />
 
-              <Stack gap="3">
+              <div :class="gridClass">
                 <div
                   v-for="item in displayItems"
                   :key="item.uuid"
@@ -107,7 +107,7 @@
                 >
                   <slot name="card" :item="item" />
                 </div>
-              </Stack>
+              </div>
 
               <slot name="pagination" />
 
@@ -169,7 +169,7 @@
           <slot name="header" />
           <slot name="filters" />
 
-          <Stack gap="3">
+          <div :class="gridClass">
             <div
               v-for="item in items"
               :key="item.uuid"
@@ -177,7 +177,7 @@
             >
               <slot name="card" :item="item" />
             </div>
-          </Stack>
+          </div>
 
           <slot name="pagination" />
 
@@ -217,6 +217,7 @@ const props = withDefaults(defineProps<{
   hoveredId?: string
   hasSubNav?: boolean
   totalCount?: number  // Total count for search bar counter (can differ from items.length with pagination)
+  gridColumns?: number  // Number of columns for card grid (1 = stack, 2/3 = grid)
 }>(), {
   loading: false,
   withMap: true,
@@ -225,7 +226,16 @@ const props = withDefaults(defineProps<{
   mapId: 'catalog-map',
   pointColor: '#3b82f6',
   hasSubNav: true,
-  totalCount: 0
+  totalCount: 0,
+  gridColumns: 1
+})
+
+// Grid class based on gridColumns prop
+const gridClass = computed(() => {
+  if (props.gridColumns === 1) return 'flex flex-col gap-3'
+  if (props.gridColumns === 2) return 'grid grid-cols-2 gap-3'
+  if (props.gridColumns === 3) return 'grid grid-cols-3 gap-3'
+  return 'flex flex-col gap-3'
 })
 
 // Smooth scroll collapse - pixel values for smooth animation