Stop waiting on network calls that never finish loading

Analytics scripts, live chat widgets, and font providers keep connections open long after your page is actually ready. Thunders used to wait for all of them anyway, on every single step.

• Build an allowlist, per project: add domains to skip during page-load checks, right from Page Stability Settings.
• Wildcards supported: use patterns like .analytics.com to cover a whole subdomain family in one entry, up to 50 domains per project.
• Only page-load checks are affected: everything else about how your tests run stays the same, you're just telling Thunders which connections aren't worth waiting on.
• Set once, apply everywhere: every test run in the project uses the same allowlist, no per-test configuration.

If a run has ever timed out on a page stability check even though the page you cared about loaded fine, a background analytics call or chat widget was probably still open. Add the domain once, and Thunders stops waiting on it across every future run.

#Sprint28