CI smoke job for the examples against locally served pages #456

What problem are you trying to solve?

CI never runs examples/, because they need a real browser and they drive live third-party sites (example.com, the-internet.herokuapp.com). When example.com stopped serving an <h1>, the Selenium mocha example's driver.wait(until.elementLocated(By.css('h1'))) timed out and the test silently stopped producing rows. That went unnoticed for weeks and was first read as a capture regression (fixed in #453). Any site change can break an example the same way, and the README and website snippets copy these examples.

What would you like DevTools to do?

A CI smoke job that runs each adapter's desktop example in trace mode with headless Chrome against pages served locally, then checks the trace it produced:

• Serve the pages the examples use (a login form, a page with a heading, a page that navigates) from a local fixture server, so the examples no longer depend on third-party content.
• Assert on the trace zip: the expected rows exist per test, deliberately failing tests show their error, and stdout carries no unexpected TimeoutError.
• Keep it to one short example per adapter so the job stays fast and stable.

Which part of DevTools would this touch?

CI workflows and examples/.

Which frameworks should this apply to?

All four adapters (desktop examples; mobile stays manual).

Anything you've tried or considered?

The conformance suite covers adapter behaviour against a fake browser and should stay the main gate. This job covers what it cannot: a real browser, the examples users copy, and the pages those examples drive. Mobile, Safari and dashboard visuals still need a person.