Onboarding: keep TUI flow exclusive

src/wizard/onboarding.ts

@@ -455,7 +455,7 @@ export async function runOnboardingWizard(
   nextConfig = applyWizardMetadata(nextConfig, { command: "onboard", mode });
   await writeConfigFile(nextConfig);
 
-  await finalizeOnboardingWizard({
+  const { launchedTui } = await finalizeOnboardingWizard({
     flow,
     opts,
     baseConfig,
@@ -465,6 +465,9 @@ export async function runOnboardingWizard(
     prompter,
     runtime,
   });
+  if (launchedTui) {
+    return;
+  }
 
   const installShell = await prompter.confirm({
     message: "Install shell completion script?",