What is run parking?
A parked run has stopped at a wall it cannot pass alone but has not been torn down. The response carries a status of "paused", a session id, a human-readable reason and the kind of challenge, and the credit reservation is refunded. The park is a handle: it is what every continuation path takes as its argument.
Why it matters
The difference between "failed" and "paused" is whether the work so far survives. A failed sign-in means re-doing the navigation, the cookie banner and the form; a parked one means handing back six digits.