The PR added APIConnectionError handling to the main request and
iteration try blocks but missed the finalization drain loop (line ~1492).
That site catches httpx transport errors to preserve an already-completed,
already-billed response when the drain iterator fails. Without the
APIConnectionError handler, an SDK-wrapped transport error during drain
would propagate uncaught and discard the completed response.
Also strengthens the test's no-payload-leak assertion to check the full
request body and URL are absent from the log message, not just the
literal string 'payload'.