feat: add UI components for skeleton, slider, sonner, spinner, switch, table, tabs, textarea, toggle group, toggle, tooltip, and mobile hook

- Implemented Skeleton component for loading placeholders.
- Created Slider component with customizable properties.
- Added Sonner component for toast notifications with icons.
- Developed Spinner component for loading indicators.
- Introduced Switch component for toggle functionality.
- Built Table component with header, body, footer, and cell subcomponents.
- Added Tabs component with list, trigger, and content subcomponents.
- Created Textarea component for user input.
- Implemented ToggleGroup and Toggle components for grouped toggle functionality.
- Developed Tooltip component with provider, trigger, and content subcomponents.
- Added useIsMobile hook to detect mobile device viewport.

src/components/ui/skeleton.tsx

@@ -0,0 +1,13 @@
+import { cn } from "@/lib/utils"
+
+function Skeleton({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="skeleton"
+      className={cn("animate-pulse rounded-md bg-muted", className)}
+      {...props}
+    />
+  )
+}
+
+export { Skeleton }