feat(reporters): add built-in "json" reporter and rename "default" to "pretty"

packages/cli/src/reporters/get.ts

@@ -0,0 +1,14 @@
+import { type Config } from '../types.js';
+import * as reporters from './index.js';
+
+export const getStandardReporter = (reporter?: Config['reporter']) => {
+  if (!reporter) {
+    return reporters.pretty;
+  }
+
+  if (typeof reporter === 'string' && reporter in reporters) {
+    return reporters[reporter as keyof typeof reporters];
+  }
+
+  return; // eslint-disable-line no-useless-return
+};