XQ#NEWPAR dispatches asynchronously on controller thread 0 and returns as
soon as it starts, not once it finishes; the dispatch time varies with
controller load. drive_axis_to_limit/find_reference followed it with a
fixed sleep before starting XQ#FES/XQ#FRM (also thread 0), which has
already needed bumping twice (0.1->0.3, 0.3->0.2) and still raced on
lgalil: sending XQ#FES while thread 0 was still busy got a '?' reply
(Galil error 19, thread already running).
Replace the fixed sleep with _wait_for_thread_idle(0), reusing the
existing is_thread_active() primitive (already used the same way in
hard_abort_and_restore_positioning_mode) to poll until thread 0 is
actually free before dispatching the next routine.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
str.strip(prefix) strips individual characters, not a literal prefix, so
replies made entirely of characters in the prefix (e.g. ":CLS0,0" for
losax) collapsed to '' and crashed float('') in describe(). Other replies
could silently truncate to a wrong value instead. Since the prefix is
already validated by _message_starts_with(), removeprefix() is a safe
drop-in fix for all affected parsers in SmaractController.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>