fix: getErrorMessage silently ignores viem's shortMessage (#430)

viem's BaseError extends Error, so the instanceof Error branch was
firing and returning error.message before the isRecord branch could
check shortMessage. Check shortMessage first inside instanceof Error
so terse viem messages are shown to users instead of verbose full ones.

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

packages/utils/src/index.ts

@@ -14,6 +14,9 @@ export function coerceString(value: unknown): string | null {
 
 export function getErrorMessage(error: unknown, fallback: string): string {
   if (error instanceof Error) {
+    // viem's BaseError extends Error and exposes a terse shortMessage; prefer it.
+    const short = coerceString((error as Record<string, unknown>).shortMessage);
+    if (short) return short;
     const msg = coerceString(error.message);
     if (msg) return msg;
   }