scripts/bench/planner_blocks_test.py restarts the null-sink controller
at $398=400 and at 1000 on one settings store and requires an answer on
the port, the depth in the status report and a move to Idle. It runs in
the grblHAL repo's CI; registered on the bench page and in the README.
BRINGUP: $398 runs over its whole range, the spin item is closed, and
the XY microstep item is committed, pushed and pinned. CAMPAIGN-LOG: the
landing and the index fix, with the host and bench proof.
No catalog consequence beyond the core submodule the motion tests
already cover; the coverage lint is clean.
ScottW514