feat: add CartButton component for consistent cart access across views

- Introduced a new CartButton component to encapsulate cart summary functionality, improving code reusability and maintainability.
- Updated MarketPage.vue and StallView.vue to utilize the CartButton component, enhancing user navigation to the cart.
- Removed redundant cart summary code from both views, streamlining the component structure.

These changes provide a unified and consistent user experience for accessing the cart across different market views.

src/modules/market/views/StallView.vue

@@ -130,14 +130,10 @@
       @add-to-cart="handleAddToCart"
     />
 
-    <!-- Cart Summary -->
-    <div v-if="marketStore.totalCartItems > 0" class="fixed bottom-4 right-4">
-      <Button @click="viewCart" class="shadow-lg">
-        <ShoppingCart class="w-5 h-5 mr-2" />
-        Cart ({{ marketStore.totalCartItems }})
-      </Button>
-    </div>
   </div>
+
+  <!-- Cart Summary -->
+  <CartButton />
 </template>
 
 <script setup lang="ts">
@@ -154,9 +150,10 @@ import {
   SelectTrigger,
   SelectValue,
 } from '@/components/ui/select'
-import { ArrowLeft, Store, X, ShoppingCart } from 'lucide-vue-next'
+import { ArrowLeft, Store, X } from 'lucide-vue-next'
 import FuzzySearch from '@/components/ui/fuzzy-search/FuzzySearch.vue'
 import ProductGrid from '../components/ProductGrid.vue'
+import CartButton from '../components/CartButton.vue'
 import type { Product, Stall } from '../types/market'
 import type { FuzzySearchOptions } from '@/composables/useFuzzySearch'
 
@@ -280,10 +277,6 @@ const handleAddToCart = (product: Product, quantity?: number) => {
   marketStore.addToStallCart(product, quantity || 1)
 }
 
-const viewCart = () => {
-  router.push('/cart')
-}
-
 
 const viewStall = (otherStallId: string) => {
   if (otherStallId !== stallId.value) {