fix: correct SVG path in loading spinner button

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/ui/button.tsx

@@ -46,7 +46,7 @@ export function Button({
       {loading && (
         <svg className="animate-spin -ml-1 mr-1 h-3.5 w-3.5" fill="none" viewBox="0 0 24 24">
           <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
-          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
+          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm16 0a8 8 0 01-8 8v0c4.627 0 8-3.373 8-8h-4z" />
         </svg>
       )}
       {children}