test: align cli runtime mocks with output runtime

src/cli/test-runtime-capture.ts

@@ -30,6 +30,12 @@ export function createCliRuntimeCapture(): CliRuntimeCapture {
       exit: (code: number) => {
         throw new Error(`__exit__:${code}`);
       },
+      writeStdout: (value: string) => {
+        runtimeLogs.push(value);
+      },
+      writeJson: (value: unknown, space = 2) => {
+        runtimeLogs.push(JSON.stringify(value, null, space > 0 ? space : undefined));
+      },
     },
     resetRuntimeCapture: () => {
       runtimeLogs.length = 0;