feat: add UI components including Skeleton, Slider, Toaster, Switch, Table, Tabs, Textarea, Toggle Group, Toggle, Tooltip, and User Avatar

- Implemented Skeleton component for loading states.
- Added Slider component using Radix UI for customizable sliders.
- Created Toaster component for notifications with theme support.
- Developed Switch component for toggle functionality.
- Introduced Table component with subcomponents for structured data display.
- Built Tabs component for tabbed navigation.
- Added Textarea component for multi-line text input.
- Implemented Toggle Group and Toggle components for grouped toggle buttons.
- Created Tooltip component for displaying additional information on hover.
- Added User Avatar component for displaying user images with fallback.
- Implemented useIsMobile hook for responsive design.
- Created API utility functions for user and thought data fetching.
- Added utility function for class name merging.
- Updated package.json with new dependencies for UI components and utilities.
- Added TypeScript configuration for path aliasing.

thoughts-frontend/components/ui/radio-group.tsx

@@ -0,0 +1,45 @@
+"use client"
+
+import * as React from "react"
+import * as RadioGroupPrimitive from "@radix-ui/react-radio-group"
+import { CircleIcon } from "lucide-react"
+
+import { cn } from "@/lib/utils"
+
+function RadioGroup({
+  className,
+  ...props
+}: React.ComponentProps<typeof RadioGroupPrimitive.Root>) {
+  return (
+    <RadioGroupPrimitive.Root
+      data-slot="radio-group"
+      className={cn("grid gap-3", className)}
+      {...props}
+    />
+  )
+}
+
+function RadioGroupItem({
+  className,
+  ...props
+}: React.ComponentProps<typeof RadioGroupPrimitive.Item>) {
+  return (
+    <RadioGroupPrimitive.Item
+      data-slot="radio-group-item"
+      className={cn(
+        "border-input text-primary focus-visible:border-ring focus-visible:ring-ring/50 aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive dark:bg-input/30 aspect-square size-4 shrink-0 rounded-full border shadow-xs transition-[color,box-shadow] outline-none focus-visible:ring-[3px] disabled:cursor-not-allowed disabled:opacity-50",
+        className
+      )}
+      {...props}
+    >
+      <RadioGroupPrimitive.Indicator
+        data-slot="radio-group-indicator"
+        className="relative flex items-center justify-center"
+      >
+        <CircleIcon className="fill-primary absolute top-1/2 left-1/2 size-2 -translate-x-1/2 -translate-y-1/2" />
+      </RadioGroupPrimitive.Indicator>
+    </RadioGroupPrimitive.Item>
+  )
+}
+
+export { RadioGroup, RadioGroupItem }