Implement shopping cart functionality with UI components and API integration

- Added CartItem, CartSummary, CartEmpty, CartSidebar, and CartSheet components for managing cart display and interactions.
- Integrated useCart and useCartUI composables for cart state management and UI control.
- Implemented API endpoints for cart operations, including fetching, adding, updating, and removing items.
- Enhanced user experience with loading states and notifications using vue-sonner for cart actions.
- Configured session management for guest and authenticated users, ensuring cart persistence across sessions.

This commit completes the shopping cart feature, enabling users to add items, view their cart, and proceed to checkout.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

app/components/ui/sheet/index.ts

@@ -0,0 +1,32 @@
+import type { VariantProps } from "class-variance-authority"
+import { cva } from "class-variance-authority"
+
+export { default as Sheet } from "./Sheet.vue"
+export { default as SheetClose } from "./SheetClose.vue"
+export { default as SheetContent } from "./SheetContent.vue"
+export { default as SheetDescription } from "./SheetDescription.vue"
+export { default as SheetFooter } from "./SheetFooter.vue"
+export { default as SheetHeader } from "./SheetHeader.vue"
+export { default as SheetTitle } from "./SheetTitle.vue"
+export { default as SheetTrigger } from "./SheetTrigger.vue"
+
+export const sheetVariants = cva(
+  "fixed z-50 gap-4 bg-background p-6 shadow-lg transition ease-in-out data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:duration-300 data-[state=open]:duration-500",
+  {
+    variants: {
+      side: {
+        top: "inset-x-0 top-0 border-b data-[state=closed]:slide-out-to-top data-[state=open]:slide-in-from-top",
+        bottom:
+            "inset-x-0 bottom-0 border-t data-[state=closed]:slide-out-to-bottom data-[state=open]:slide-in-from-bottom",
+        left: "inset-y-0 left-0 h-full w-3/4 border-r data-[state=closed]:slide-out-to-left data-[state=open]:slide-in-from-left sm:max-w-sm",
+        right:
+            "inset-y-0 right-0 h-full w-3/4 border-l data-[state=closed]:slide-out-to-right data-[state=open]:slide-in-from-right sm:max-w-sm",
+      },
+    },
+    defaultVariants: {
+      side: "right",
+    },
+  },
+)
+
+export type SheetVariants = VariantProps<typeof sheetVariants>