Leave the lens to the cloud client in cloud mode

cloud.verdict-hold printed to completion and then failed its hand-back on
head/z_mode=0. That job's header carried ZSmd 0, gfhardware's
set_mode_from_puls turns that into z_mode 0, and z_mode 0 is full step
(lenshome.c): the cloud client had set the lens the way the pulse file it
was playing asked. Nothing was left behind - the machine did what the job
said.

The baseline already skips nine attributes in cloud mode, for the reason
written above the list: the cloud client sets its own values for them
from every pulse header, and forcing the GRBL values under it would be
the baseline configuring another controller's machine. head/z_current and
head/z_mode are the same thing and were not on the list. They are now, in
cloud mode only; in GRBL mode the pair is still checked against 1 and 1,
which is the half of this an exemption could quietly break, so a test
holds it.

Host-proven: 89 baseline unit tests.

forgetest/forgetest/baseline.py

@@ -87,9 +87,14 @@ FIXED_SYSFS = [
 # every pulse header (step_freq 10 kHz, the run currents), runs at the
 # service's own x8 with the module's ramp whatever xy_microsteps says, and
 # hands the hold currents back at idle; forcing the GRBL values under it
-# would be the baseline configuring another controller's machine.
+# would be the baseline configuring another controller's machine. The Z
+# pair belongs with them: the cloud client takes the lens microstep mode
+# from the pulse header it is playing (ZSmd, gfhardware z_axis
+# set_mode_from_puls) and the current with it, so a job whose header asks
+# for full step leaves z_mode 0 behind by doing what it was told.
 GRBL_CONTROLLER_SYSFS = ("cnc/motor_lock", "cnc/x_mode", "cnc/y_mode", "cnc/x_decay", "cnc/y_decay",
-                         "cnc/step_freq", "cnc/ramp_rate", "pic/x_step_current", "pic/y_step_current")
+                         "cnc/step_freq", "cnc/ramp_rate", "pic/x_step_current", "pic/y_step_current",
+                         "head/z_current", "head/z_mode")
 
 # Settings the baseline never hands back as bare settings: controller_mode
 # is the persisted mirror of the live mode (the mode item restores it