fix: add typeof string type guard for toast description in anchored toast

The floating toast correctly guarded with typeof toast.description === 'string'
before passing to CopyErrorButton, but the anchored toast only checked truthiness.
This could pass non-string values (e.g. React nodes) to clipboard.writeText().

Author: cursoragent

apps/web/src/components/ui/toast.tsx

@@ -405,7 +405,7 @@ function AnchoredToasts() {
                               className="min-w-0 break-words font-medium"
                               data-slot="toast-title"
                             />
-                            {toast.type === "error" && toast.description && (
+                            {toast.type === "error" && typeof toast.description === "string" && (
                               <CopyErrorButton text={toast.description} />
                             )}
                           </div>