Chunk recovery production harness

This unlinked, noindex page exercises the real global error boundary. Nothing happens until a simulation button is pressed.

Both simulations intentionally create Sentry events. The persistent simulation also reaches the normal error page and sends the support-ticket email.

Recoverable failure

Expected result: a brief recovery message, one hard refresh, then a green success message on this page. No support-ticket email.

Persistent failure

Expected result: one hard refresh, a second simulated failure, then the normal error page and support-ticket email. Click its Reload page button to return here and finish cleanup.