Made of little things.

import {createRequire} from 'node:module';
import {realpathSync,readFileSync} from 'node:fs';
import assert from 'node:assert/strict';
const require=createRequire(realpathSync(new URL('../node_modules/@napplet/conformance-cli/package.json',import.meta.url)));
const {chromium}=require('playwright');
const browser=await chromium.launch({headless:true});
try {
 const page=await browser.newPage({viewport:{width:900,height:600}}),errors=[];page.on('pageerror',e=>errors.push(e.message));
 await page.setContent('<iframe sandbox="allow-scripts" style="width:900px;height:600px;border:0"></iframe>');
 await page.locator('iframe').evaluate((el,html)=>el.srcdoc=html,readFileSync(new URL('../dist/index.html',import.meta.url),'utf8'));
 await page.waitForTimeout(200);const f=page.frames().find(f=>f.url()==='about:srcdoc');assert.ok(f);
 await f.locator('[data-preset="runner"]').click();await f.locator('#race').click();await f.locator('#message-title').filter({hasText:'Look at you go.'}).waitFor({timeout:30000});
 assert.equal(await f.locator('.score-row').count(),1);assert.equal(await f.locator('#share-result').isVisible(),false);assert.match(await f.locator('#hint').innerText(),/session/);
 await f.locator('#message-action').click();await f.locator('#shared').click();assert.match(await f.locator('#score-status').innerText(),/unavailable/);assert.deepEqual(errors,[]);
 await f.locator('#track-picker').click();await f.locator('#create-level').click();await f.getByRole('button',{name:'+ Step up',exact:true}).click();await f.locator('#save-level').click();assert.match(await f.locator('#level-status').innerText(),/session/);await f.locator('#publish-level').click();await f.locator('#level-status').filter({hasText:'updated public-level sharing support'}).waitFor();await f.locator('#test-level').click();assert.equal(await f.locator('#track-number').innerText(),'CUSTOM');assert.deepEqual(errors,[]);
 console.log('PASS: full race with no injected optional domains; clear storage and shared-score fallbacks.');
} finally {await browser.close();}