Live verification of the previous commit showed the immediate retry STILL
stranded: deleting a finished Job leaves it terminating (job-tracking
finalizer), so the re-Create collided with the dying object and was
mapped to ErrAlreadyExists a second time. Poll until the name actually
frees (bounded, ~10s) and surface a 'retry shortly' error if a stuck
finalizer ever outlives the budget. Fake-client tests pin both the
replace-finished and coalesce-in-flight branches.
Lemon-miaow
e690b058db