The job is known but its result is not readable yet — keep polling.
Returned in two situations, both of which mean "ask again", never "you are done":
the job has not produced its result yet, or the job reached a terminal status while
its stored result could not be read back. The response body is an empty object: it
deliberately carries no state, so a client cannot mistake it for a finished result.
Treat any 202 as a signal to continue the poll loop under your existing timeout.
Never treat it as a terminal outcome.
Backtesting execution result