setup: initialize project with package.json, tsconfig, tsup, vitest, src skeleton, and test placeholders

test/error/errors.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('errors', () => {
+  it('placeholder', () => {
+    expect(true).toBe(true);
+  });
+});