feat: implement Figlet, Pastel, and Unit tools with a unified layout

- Add Figlet text converter with font selection and history
- Add Pastel color palette generator and manipulation suite
- Add comprehensive Units converter with category-based logic
- Introduce AppShell with Sidebar and Header for navigation
- Modernize theme system with CSS variables and new animations
- Update project configuration and dependencies

components/ui/Badge.tsx

@@ -0,0 +1,35 @@
+'use client';
+
+import * as React from 'react';
+import { cn } from '@/lib/utils/cn';
+
+export interface BadgeProps extends React.HTMLAttributes<HTMLDivElement> {
+  variant?: 'default' | 'success' | 'warning' | 'destructive' | 'outline';
+}
+
+const Badge = React.forwardRef<HTMLDivElement, BadgeProps>(
+  ({ className, variant = 'default', ...props }, ref) => {
+    return (
+      <div
+        ref={ref}
+        className={cn(
+          'inline-flex items-center rounded-full px-2.5 py-0.5 text-xs font-semibold transition-colors',
+          'focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2',
+          {
+            'bg-primary text-primary-foreground': variant === 'default',
+            'bg-green-500 text-white': variant === 'success',
+            'bg-yellow-500 text-white': variant === 'warning',
+            'bg-destructive text-destructive-foreground': variant === 'destructive',
+            'border border-input': variant === 'outline',
+          },
+          className
+        )}
+        {...props}
+      />
+    );
+  }
+);
+
+Badge.displayName = 'Badge';
+
+export { Badge };