test: make the iOS simulator suite survive a slow openurl

[rexxars]

The iOS job went red on main with Failed to open ... Operation timed out (NSPOSIXErrorDomain code 60) out of xcrun simctl openurl, on a simulator that had booted fine a minute earlier. The run before it, same code, passed - so this is a race rather than something being broken.

openurl hands the URL to Safari and waits for it to accept it, and it gives up after roughly ten seconds. On a runner that needs two minutes just to boot the simulator, Safari cold-starting does not fit in that window. Locally openurl returns in well under a second, which is why this only turns up in CI.

So two changes:

bootSimulator() now launches Safari once the device has finished booting. That pays the first-launch cost inside the boot step, where nothing is timing it, and it is the reason the pre-boot step exists in the first place.

openPage retries openurl a couple of times if it still loses the race, terminating Safari before each retry. Restarting rather than just asking again is deliberate: a timed-out openurl may still have navigated, and a second tester page would then connect under the same session id.

What to review

The retry is the part I would look at. I could not reproduce the timeout locally, so I exercised the retry path by injecting a failure on the first attempt and confirmed the suite still ran, then reverted that. The three runs on this branch all passed without needing the retry at all, meaning the warm launch was enough each time - which is good news for the fix but does leave the retry itself only covered by the injected failure.

If it ever comes back, the log now says Opening it failed (attempt N of 3), so we will know whether the retry saved it or whether ten seconds is simply not the real constraint.