refactor: consolidate shared application helpers

lib/utils.ts

@@ -5,6 +5,10 @@ export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
 }
 
+export function getErrorMessage(error: unknown, fallback: string) {
+  return error instanceof Error ? error.message : fallback;
+}
+
 export const stripHtml = (html: string) => {
   return (html || "").replace(/<[^>]*>?/gm, '').trim();
 };
@@ -17,4 +21,4 @@ export const copyToClipboard = async (text: string): Promise<boolean> => {
         console.error("Copy error:", error);
         return false;
   }
-};
+};