initial: standalone repo from monorepo split

src/components/ui/button.tsx

@@ -0,0 +1,42 @@
+import { forwardRef } from 'react';
+
+interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'danger' | 'ghost';
+  size?: 'sm' | 'md';
+  loading?: boolean;
+}
+
+const variantStyles: Record<string, string> = {
+  primary: 'bg-primary-600 text-white shadow-sm hover:bg-primary-700 focus:ring-primary-500/50',
+  secondary: 'bg-white dark:bg-surface-800 text-surface-700 dark:text-surface-200 border border-surface-200 dark:border-surface-600 hover:bg-surface-50 dark:hover:bg-surface-700 focus:ring-surface-300/50',
+  danger: 'bg-red-600 text-white shadow-sm hover:bg-red-700 focus:ring-red-500/50',
+  ghost: 'text-surface-500 dark:text-surface-400 hover:text-surface-800 dark:hover:text-surface-200 hover:bg-surface-50 dark:hover:bg-surface-700',
+};
+
+const sizeStyles: Record<string, string> = {
+  sm: 'px-3 py-1.5 text-xs',
+  md: 'px-4 py-2 text-sm',
+};
+
+export const Button = forwardRef<HTMLButtonElement, ButtonProps>(
+  ({ variant = 'primary', size = 'md', loading, children, disabled, className = '', ...props }, ref) => {
+    return (
+      <button
+        ref={ref}
+        disabled={disabled || loading}
+        className={`inline-flex items-center justify-center gap-2 font-medium rounded-lg transition-all duration-200 cursor-pointer disabled:opacity-50 disabled:cursor-not-allowed focus:outline-none focus:ring-2 focus:ring-offset-2 ${variantStyles[variant]} ${sizeStyles[size]} ${className}`}
+        {...props}
+      >
+        {loading && (
+          <svg className="animate-spin h-3.5 w-3.5" viewBox="0 0 24 24" fill="none" aria-hidden="true">
+            <circle cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="3" className="opacity-25" />
+            <path d="M4 12a8 8 0 018-8" stroke="currentColor" strokeWidth="3" strokeLinecap="round" />
+          </svg>
+        )}
+        {children}
+      </button>
+    );
+  },
+);
+
+Button.displayName = 'Button';