fix(build): modernize package configuration and simplify tests for the current toolchain

test/test.node.ts

@@ -0,0 +1,11 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartsign from '../ts/index.js';
+
+let testSmartSign: smartsign.SmartSign;
+
+tap.test('should create a new SmartSign instance', async () => {
+  testSmartSign = new smartsign.SmartSign(Buffer.from('test certificate'));
+  expect(testSmartSign).toBeInstanceOf(smartsign.SmartSign);
+});
+
+export default tap.start();