feat: add templates, history, comparison mode, animations, and empty states

- Add text templates with 16 pre-made options across 4 categories (greeting, tech, fun, seasonal)
- Add copy history panel tracking last 10 copied items with restore functionality
- Add font comparison mode to view multiple fonts side-by-side (up to 6 fonts)
- Add smooth animations: slide-down, slide-up, scale-in, fade-in, pulse, and shimmer
- Add loading skeletons for better perceived performance
- Add EmptyState component with contextual messages and icons
- Add hover effects and transitions throughout the UI
- Improve visual feedback with animated badges and shadows

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

Co-Authored-By: Claude <noreply@anthropic.com>

components/ui/EmptyState.tsx

@@ -0,0 +1,36 @@
+import * as React from 'react';
+import { cn } from '@/lib/utils/cn';
+import { LucideIcon } from 'lucide-react';
+
+export interface EmptyStateProps {
+  icon?: LucideIcon;
+  title: string;
+  description?: string;
+  action?: React.ReactNode;
+  className?: string;
+}
+
+export function EmptyState({
+  icon: Icon,
+  title,
+  description,
+  action,
+  className,
+}: EmptyStateProps) {
+  return (
+    <div className={cn('flex flex-col items-center justify-center py-12 px-4 text-center', className)}>
+      {Icon && (
+        <div className="mb-4 rounded-full bg-muted p-3">
+          <Icon className="h-6 w-6 text-muted-foreground" />
+        </div>
+      )}
+      <h3 className="mb-2 text-sm font-semibold">{title}</h3>
+      {description && (
+        <p className="mb-4 text-sm text-muted-foreground max-w-sm">
+          {description}
+        </p>
+      )}
+      {action}
+    </div>
+  );
+}

components/ui/Skeleton.tsx

@@ -0,0 +1,22 @@
+import { cn } from '@/lib/utils/cn';
+
+export interface SkeletonProps extends React.HTMLAttributes<HTMLDivElement> {}
+
+export function Skeleton({ className, ...props }: SkeletonProps) {
+  return (
+    <div
+      className={cn('animate-pulse rounded-md bg-muted', className)}
+      {...props}
+    />
+  );
+}
+
+export function SkeletonText({ className, ...props }: SkeletonProps) {
+  return (
+    <div className={cn('space-y-2', className)} {...props}>
+      <Skeleton className="h-4 w-full" />
+      <Skeleton className="h-4 w-5/6" />
+      <Skeleton className="h-4 w-4/6" />
+    </div>
+  );
+}