The x32 default landed in forgetest/baseline.py and the driver, but two
callers still judged the machine at x8 and both failed on the host.
forgetest/tests/test_baseline.py: setUp seeded the fake machine from the x8
FIXED_SYSFS literals while enforce() compares against fixed_sysfs() of the
resolved mode, so x_mode, y_mode, step_freq and ramp_rate read as deviations
on a clean machine - 23 failures across BaselineTests and
TransientNotLeftoverTests. It seeds from fixed_sysfs() now, and the tick
expectations come from it (DEFAULT_TICK) rather than a typed 28160. The
xy_mode_of and ref_xy_mode unset/invalid cases expect 32, with an explicit
"8" case added that had no coverage. Two reference_preconfig dumps taken on
an x8 machine carry xy_microsteps = 8, because the markers are read at the
reference's own mode. wait_configured wrote the static CONFIGURED_MARKERS
where the function watches configured_markers() of the mode in force, and
the held-controller jog typed 221 steps for "4.144 mm", which is 1.036 mm at
x32; both derive from the mode now. 69 tests, all pass.
scripts/bench/laser_stream_test.py: STEPS_PER_MM was the x8 53.333, so the
X-peak check failed at 2133 steps against an expected 533. The whole harness
now derives from XY_MICROSTEPS_BASE/DEFAULT the way glowforge.h and
baseline.py do, which uncovered five more x8-only expectations behind the
first: the machine tick, the fire-gap limit (it grows as sqrt(k), not k - a
finer mode shortens the accel interval by sqrt(k) while speeding the tick by
k), the rung split in fire_spans, the density period and minimum burst
(laser_pulse_ticks is in x8 ticks and the stream scales it, so the config
keeps the x8 numbers and the measured lengths scale), and the decel/hold
budgets. Run against the null-sink build: all stream emission rules hold.
xy_mode_test.py's docstring still described the no-key case as x8 while its
own assertions had moved to x32.
No behavior change and no acceptance-catalog consequence: these are test
expectations and a bench harness, not image component sources. The coverage
lint is unchanged at 0 uncovered paths.
The GRBL driver's stream engine and its motion envelope change
(grblHAL-glowforge: the shipper writes outside the lock, a clamp inside
an armed window faults, the X/Y soft limits follow the home, the
machine's settings are pinned, the homing keys are clamped). This commit
carries the host rules and the catalog tests that hold them; the driver
commit follows, because its CI fetches these harnesses unpinned.
scripts/bench/laser_stream_test.py:
- Rule 28: a 300 ms producer stall while armed faults the stream with
ALARM:17, the kernel sees no step burst (at most the planned steps per
100 ticks), the stream ends dark, the latch sideband ends on the lock.
The same stall unarmed is a warning: the move completes with every
step, the clamp visible as the burst the kernel counts.
- Rule 29: a 300 ms stall of the sink's write leaves the producer on
pace: no clamp, every step, lit through, dark at the end.
- The stand-in engine takes GFSINK_STALL_MS and GFSINK_WRITE_STALL_MS,
null-sink only.
scripts/bench/z_envelope_test.py:
- Rule 10: homed (a gfcloud home), a program move past X max, Y max or
the near edge alarms with ALARM:2 before any motion, a jog past the bed
is refused with error 15, a move inside the bed runs, and a $20 write
keeps the limits. The core repeats the last error for the line after a
refused jog until an empty line clears it, so the rule sends one.
forgetest/forgetest/suite/motion.py:
- motion.soft-limits (kind auto, no emission): homes through the cloud
suite's gfhome homing when the machine is not homed, then the three
refusals (ALARM:2, the kernel counters still), the refused jog, the
inside move, and the return to the corner read at rest.
- motion.deadman phase 2b: a 100 ms SIGSTOP mid-move, inside the
kernel's queue: no underrun, the controller's log warns of the clamped
late events, the move completes with every step (read at rest), the
latch stays locked. The armed clamp is proven on the host (rule 28).
forgetest/forgetest/suite/cloud.py:
- gfhome_homing drains the driver's answer to $H once the session ends:
it sits behind the status reports and passed for the reply to the
caller's next command (a setting read as None).
forgetest/forgetest/baseline.py:
- The hand-back reads the position counters at the kernel's own
microstep mode (cnc/x_mode, read before the sysfs restore puts the
settings' mode back). At the x8 constant, an x32 machine's 30 mm read
as 120 mm, beyond the return bound, and the displaced head was left in
place. The dead band scales the same way. tests/test_baseline.py holds
both.
Proof. Host: stream rules 1 to 29 and z_envelope rules 1 to 10 against
the null-sink driver, the forgetest unit tests. Bench reference:
motion.soft-limits passed (X 495 and Y 279 refused with ALARM:2 and
0.000 mm of kernel motion, X-1 the same, the jog error:15, the inside
move ran, back at the corner 0.0/0.0 mm); motion.deadman passed with
the new phase (92 late events clamped, max behind 92.3 ms, no underrun,
30.0 mm counted, latch locked) and the hand-back jogged the head back
under the x32 scale.
The GRBL driver's emission gates change (grblHAL-glowforge: the per-tick
fire gate, the latch with an owner, the cooling verdict's two tiers, and
the arm-flow gates). This commit carries the host rules and the catalog
tests that hold them; the driver commit follows, because its CI fetches
these harnesses unpinned.
scripts/bench/laser_stream_test.py:
- Rule 24 is the verdict's pause tier: the client holds the job under the
open window, the first deceleration runs lit to the stop (the dark lead
before the stop is at most 1000 ticks: the producer's lead plus one
shipper period), a resume under the standing verdict moves dark and is
held again, the clean verdict resumes lit with no press, and the latch
sideband carries only the arm's unlock and the program end's lock.
- Rule 25 is the fail tier: AIRFLOW mid-cut ends the job with ALARM:3,
the stream ends dark well short of the line, the sideband ends on the
lock, and a resume under the clean verdict that follows resumes nothing.
- Rule 26: a sender change mid-M3 holds the job with the deceleration
dark: the gate follows the window on every tick.
- Rule 27: a verdict that goes stale holds the job at the cache's own
expiry, lit to the stop, never a poll later; the engine's return
resumes lit.
- The stand-in engine publishes the verdict name and has a stale mode;
the session steps gain expect_text, reconnect and a wait_state timeout;
every session reads the latch sideband (GFSINK_LATCH_LOG).
scripts/bench/laser_lifecycle_test.py:
- Rules 11 to 15: the pause tier resumes with no press and no prompt, the
fail tier ends the job and nothing resumes it, a sender change during a
re-arm cancels it, a jog does not hold the window open, and a press
counts only after the button has been seen up. The stand-in engine
takes a live verdict dict. start_armed_move waits for a fresh prompt
and a fresh armed message: a press that lands before the wait has
begun is not consent, and the old stale match let one land early.
forgetest/forgetest/suite/laser.py:
- laser.verdict-cut (kind live, one press): a 40 mm M3 line; the test
pauses the daemon for 3.5 s so the verdict goes stale (the settings
route is idle-gated and the engine reloads its gates at a session
start, so no setting can trip a pause mid-cut; the crash tiers need a
physical knock). The controller must hold with the SoC latch and the
hardware button latch both clear in every sample, emission must read 0
before the resume, and the clean verdict must resume the cut lit with
no press and no prompt; M2 disarms as usual.
- laser.armed-kill asserts that the respawned controller comes up with
the latch still locked.
Proof: both harnesses pass against the driver change on the host, and
the forgetest unit tests pass. On the bench reference, laser.verdict-cut
passed with no gap in the cut (held at +1.71 s after the pause began,
both latches clear in every sample, emission 0 at +2.06 s after the
hold, resumed lit at +4.0 s with the beam detector 678 counts over idle,
kernel drift 0.0 mm, disarmed 0.1 s after Idle) and laser.armed-kill
passed (emission 0 at +1.8 s after the supervisor's stop and +2.1 s
after the SIGKILL, latch locked, respawned with the latch locked, button
dark). Two earlier verdict-cut runs shaped the driver: a pause that
locked the latch resumed dark, because a lock sets the hardware button
latch, and a hold taken a poll after the gate closed left a several-mm
gap.
Catalog: one test added and one extended; both cover src/** of the
driver through the existing laser covers.
The Z session used to reference the lens itself with M103, which is gone:
the daemon sweeps the lens onto its hall edge before a controller starts
and leaves a marker, and the controller opens the Z envelope on that. No
daemon runs behind the harness, so nothing wrote the marker and every Z
move was refused, which is what the session's first move ran into.
The runner now writes the marker the daemon writes, and the session pins
lens_hall_edge_z_mm so the moves are counted from a known height: Z3 is 9
half-steps on the screw and Z4 is 12, so a 1 mm move up and back is 3
steps each way.
This is also the check that caught the controller overwriting its own
referenced Z at start, which the panel could not show.
The lens now takes its hall-edge reference before any controller starts,
so Z is referenced on every start and M103 is gone. The laser-stream
harness opened its Z session by referencing the lens the way a
commissioning card did; it no longer has to, because Z is already open by
the time the session runs.
forgectrl.panel-serves gains the assertions for the per-axis reference:
homed_axes is an axis mask, homed agrees with it, and with a controller
running Z is referenced and reads inside the lens reach the same document
reports. That last check is the one that catches a panel showing nothing
for a Z the controller holds.
commission.check-motion already exercised the new path, because the
motion wizard's probe runs the same sequence the supervisor does, so its
covers map gains lenshome.c and its description names the lens reference
and the hard fault behind it.
The open item "Idle before the kernel drains" asked to decide between
holding Idle until the kernel drains and stopping the continuation pads
growing the lag. Measured first: on the machine, four chained 50 mm jogs
against cnc/state give 171, 175, 177 and 176 ms after Idle. One queue
depth, flat. The growth the item described is gone, so neither driver
change was made and the item is closed.
Host side agrees and says where the mechanism lives. Stream bytes are the
time axis, so a dumped stream's length is how long the machine plays it:
chained jogs produce 35755 bytes each with no growth, and the churn
session holds at 64790 bytes at a producer lead of 2 or 10 ms. Only above
the lead ceiling does it inflate. Rule 17 now holds that stream to a
budget derived from the job rather than to a recorded number, so the
inflation regime cannot return unnoticed; it fails at 5899 and 8005 ms
with the ceiling lifted and passes at 2301 against 3800.
BRINGUP carried a second error. It said every forgectrl path that stops
the controller after motion waits for cnc/state idle. super.c says
outright that POST /controller/stop is not idle-gated, because it is also
the emergency lever, and safes the machine with cnc/stop and the latch
before the signal instead. The mode switch, the cooling gate and the
daemon shutdown do gate on machine_is_idle(). Both the tail figure and
the gating claim are corrected, and CAMPAIGN-LOG carries the measurements
and the decision not to hold Idle.
Acceptance: rule 17 is a host harness rule in the grblHAL repo's CI, not
a catalog case. The catalog is unchanged because no machine behavior is:
the driver change is a bound on an out-of-range knob.
meta-forgefirm: the forgefirm-users init replays the account at boot;
sshd refuses root and empty passwords and runs only while the panel
turns it on; the release image keeps an empty root password for the
console; the console banner; avahi announces forgefirm.local; https in
libmicrohttpd and ulfius; the panel on 80 and 443; the license bundle on
the rootfs; release.sh checks the root policy on the built rootfs.
forgetest: the commission suites (commission, commission_dark,
commission_sheet: 23 cases); the runner turns cloud mode on with the
typed phrase for a test that declares it; the baseline's motor_lock is
0; the log-export test checks the bundle for the camera key; the record
helpers write bytes as given and join the daemon's paths as POSIX. The
stream harness gains rule 24: a hold verdict is held again after a
resume. Bench drills: lens_travel.py and lens_stop_accel.py.
Docs: BRINGUP carries the present state; CAMPAIGN-LOG carries the dated
record.
The cooling verdict now carries the engine's own armed flag, so the
stand-in engines in both null-sink harnesses publish it. The lifecycle
harness gains two cases: an engine that never takes the armed window
must produce a refused arm and no emission, and one that takes it a
couple of seconds late must produce a wait and then a normal arm. The
late case is the one that proves the controller keeps reading the
verdict while it is blocked in the arm; without that every job would
fail there.
The emission witness gains the bench form of the same rule: no sample
may show the laser firing while the cooling engine reports a phase that
runs the fans at their idle duty. That is what a burn with no airflow
looks like from the outside, and nothing in the catalog looked for it.
Rule 22: M3 S1000 with the window open, then jogs from Idle (a sender's
Fire button plus its Move panel) ship every jog tick dark, and the cut
after them is lit. Rule 23: two cuts at S300 and S1000 queued together
render the S300 cruise at the S300 density; the rolloff shapes against
the segment's own velocity ratio, never the newest S over the block's.
Both fail on the driver before its fix.
Stream harness rule 21: a feed hold leaves no dark ground in either mode (lit into the hold, dark while held, lit from the first step out), with realtime and wait-state steps in the session runner. Lifecycle harness: the hold a sender change puts a running job into, the resume that re-arms a held job from the sender and from the button, a reset from a held job, and the resume after the grace closed the window in Hold. Live-fire drills: holdres (the pause as a corner in time, the re-arm after the grace); senderchg follows the hold. BRINGUP: the gapless-pause and sender-change items close, the facts bank gains the measured hold and resume behavior; CAMPAIGN-LOG records the proof and the bench runs. Acceptance: the pause-resume-lid-cancel text follows the behavior; the driver stays covered by src/**.
The stream harness gains rule 20: under M4 with the curve in force, the
accelerate-in head of a line renders less density at the default gamma
of 2 than at gamma 1 (0.317 against 0.537 on the host grid) while the
cruise middle renders identically - the exponent shapes only the
velocity-scaled rolloff, never the programmed level. The panel-serves
covers widen to the whole recorder (src/curverec.*). BRINGUP describes
the rolloff and the one-press recorder; the MOTION table gains
laser_corner_gamma; the panel help explains the knob.
The stream harness gains rule 19: with the bench-default curve in force
a ladder of S rungs renders the curve's densities exactly (half light
lands near 80 percent density), monotonic, floored and ceiled by
$35/$36; every other session pins laser_dose_curve = off so its
S-to-level arithmetic stays exact, and the arm-report checks carry the
curve name. The lifecycle harness asserts the published state file
names the curve in force. The catalog's forgectrl.panel-serves asserts
the curve field in the grbl report, /curve/status and the ladder
G-code, and its covers name the recorder.
BRINGUP describes S-commands-light through the measured curve and the
owner recorder; the MOTION table gains laser_dose_curve; LIGHTBURN
tells the operator power now means light and how to record their own
tube's curve from the panel.
The stream harness keeps the analog rendering as the host-test
conservatism reference (rule 13's mask, the duty ladders) and drops the
M101 switch sessions; rule 18 stays as the derived-floor proof, now
satisfied from boot by the precompute. The lifecycle harness's
state-files scenario asserts the derived floor is in $$ before any arm.
The catalog's laser.power-model-switch goes and laser.power-floor reads
the one floor key with no M-code needed. The mswitch drill goes; the
m4corner drill becomes a single density pass; the dpatch drill returns
to density only.
The CAMPAIGN-LOG records the first rasters (254 and 508 DPI grayscale
wedges: tonality held to ~14 pulse slots per pixel, no dither artifact,
one benign stale-verdict suppression under CPU starvation) and the
decision that ends the analog mode - the strike transient fires a spot
at every beam-on, and the finish comparison found no advantage. BRINGUP,
LIGHTBURN, MOTION and SAFETY describe the density-only present.
The stream harness gains rules 18 to 21: the floor is derived from the
selected model's config key at the arm and a typed $35 is overwritten;
M101 switches the rendering exactly at the boundary in both directions
with no continuous FIRE at full duty across it; a refused switch (the
spindle on) leaves the stream unchanged, and the harness resyncs with
an empty line because the core skips G-code after an error until the
sender resyncs; M2 reverts a program-scoped switch and Q1 holds. The
analog sessions pin laser_floor_analog at the density floor so the
existing duty expectations stand, and the density ladder's unfloored
run moves from a chained $35 write to the laser_floor_density key.
The catalog's laser.power-floor becomes model-aware: it reads the
configured model and the floor keys from forgectrl, switches to the
configured model with M101 so the derivation runs without a fire, and
expects $35 to be that model's floor. The new laser.power-model-switch
switches to each model with the spindle off, checks the reported
message and $35 after each switch, and checks the M2 revert. The new
mswitch bench drill runs the switch on the machine in one armed run.
Docs follow: BRINGUP's Laser control section describes the switch, the
derived floors and the measured dose response of both models; the
MOTION settings table gains the five keys; LIGHTBURN gains a Power
models section and drops the stale 30 percent floor advice; SAFETY
names the switch's refusal rule; the CAMPAIGN-LOG records the judged
depth-witness runs of 2026-08-30 and the switch's host and bench proof.
Stream harness rules 16 and 17 with their sessions: an M5 executed with
the planner drained and the kernel run over must darken the rapids that
follow it (m5-idle), and a job whose M3 runs at the level the previous
job ended at must still fire its first cut (next-job). The second rule
is the core's contract: set_state records the rpm and the per-segment
update is skipped while it is unchanged, so the driver's set_state is
the only thing that can light that move. Both sessions run under both
dose models; the bench build that went dark on its second job fails
next-job with one fire span.
Bench drills: pcurve (a per-level ladder of 100 mm lines read from the
HV current and the head thermopile at 25 Hz, with the instrument checks
and the JSON record) and m5dark (one line, M5, two rapids, judged on the
current trace and laser_on_sampled until the armed window closes).
Catalog: laser.m5-rapid-dark, a live test of the M5 case (46 tests; the
counts in BRINGUP follow). CAMPAIGN-LOG carries the day's record: the
two curve ladders, the defect pair, the root cause, the host and bench
proof.
grblHAL-glowforge 03d70e0, pinned here, makes density the shipped model
and $35 the density floor at 10. Every analog session in the stream
harness now selects its model rather than inheriting it: without that the
flip would have quietly turned them into density runs and taken the
analog fallback's coverage with them. laser.power-floor carries the new
floor and its PWMSAR minimum, and its description no longer describes
$35 as a duty floor.
All ten stream sessions pass on the new defaults, with the analog duties
shifting exactly as the floor predicts - min_value 12, gradient 0.115 -
along with both C harnesses and the lifecycle harness.
Recorded in BRINGUP and the campaign log, including what the defaults
rest on and what they do not: the seven ladders ran at F300 and F100 at
constant power, so production feeds, M4 into corners and the raster path
remain unproven on hardware.
Rule 15 in the stream harness holds both halves of the minimum
(grblHAL-glowforge f7e8c17, pinned here): no emitted burst falls below
laser_pulse_min_ticks, excepting one clipped by fire going off mid-burst,
and the levels too faint to fill a window still render their exact
average density. Checked against a run at minimum 1 so it cannot pass
vacuously - level 2 goes from 444 bursts of one tick to 147 of three at
the same density, and levels already above the minimum are unchanged.
Four bench ladders settle the base period at 20. The same six rungs
marked in all of them, and the matched pairs across periods separate the
variables: at identical pulse length, halving the density killed the
mark; at identical density, varying the pulse 3x changed nothing. Feed
does not move it either - 10 percent at F100 carries 44 percent more
energy per mm than 20 percent at F300, which marks, and still left
nothing. The low-end marking limit is average power, not dose per length
and not pulse length.
The F100 trace separates two failures that look alike on the material:
seven current segments for eight rungs, anchored by a flat saturated
final segment that can only be full density, put 5 percent at no
discharge at all and 10 percent at a full 15 seconds of current with no
mark. Only the first is ours, and the minimum pulse is the answer to it.
Also recorded: the factory's Precision Power 1 runs a 19.53 percent FIRE
duty cycle at full PWM duty, and its 1-100 scale maps onto density
18.9-79.5 percent, so its 1 percent is the bottom of the useful band
rather than 1 percent of the range. Under the density model $35 and $36
are that same control - a density floor and ceiling - which makes the
user-facing scale a settings choice rather than new code.
Four new sessions in the stream harness cover the model (grblHAL-glowforge
2bca017, pinned here). Density renders the commanded level exactly -
levels 2, 3, 7, 15, 25 and 38 came back as 0.0158, 0.0237, 0.0551,
0.1182, 0.1969 and 0.2993 against level/127 of 0.01575, 0.02362, 0.05512,
0.11811, 0.19685 and 0.29921 - S1000 renders 1.0000 and still ends dark,
every power byte carries full duty, and a level change inside a run costs
no stream byte where analog ships one per level.
Rule 13 is the one worth having: the same job run under both models
produces an identical motion grid tick for tick, and all 20051 density
FIRE ticks fall inside the 169776 the analog run fired. The model masks
the core's fire state and never sources one, measured rather than argued.
Rule 14 covers the idle-gap fix: a standalone S between moves, from a
sender slow enough to drain the planner, now fires each move at its own
level (28338 ticks each at duties 30, 52 and 84). Before the fix duty 30
held all 85014 and the other two levels never appeared. That closes
"Next work" item 18, which this work opened earlier today.
The harness now derives its expectations from the board's floor and
chains two launches over one settings file, because the core precomputes
the S to duty mapping once when the spindle is enabled: $35 written at
runtime persists and reports immediately but only enters force at the
next controller start. That is recorded in BRINGUP beside the existing
defaults note, and laser.power-floor's failure message now says so.
Acceptance: the density path shipping off by default is inert until
laser_power_model is set, and the laser tests' covers already name
grblhal-glowforge src/**; the model's own acceptance test waits on the
bench drill that picks the base period.
The pthresh ladder on scrap puts the tube's two thresholds far apart: the
discharge strikes between 2 and 3 percent duty, but nothing lases usefully
below 16 percent (PWMSAR 20), and the rungs between show only a spot at
each line start. $35 ships at 16 (grblhal-glowforge 9466f76, pinned here).
The drill said current lift-off and first mark share a rung; this run
falsifies that, so its docstring and read-the-material text now name both
thresholds and warn that a start-of-line spot is below the threshold, not
at it.
A start-of-line spot is also what a full-power leak at a kernel run start
would look like, so laser_stream_test gains a ladder session (rule 10):
every FIRE tick must ride a commanded duty, and the fire ticks must divide
evenly across rungs. Both hold exactly - six commanded duties, no others,
and 28296 fire ticks on every rung - so the spots are the tube, not the
stream. The harness now derives its expectations from the floor, which
moves the M4 session's S500 plateau from 63 to 73.
laser.power-floor is a new auto acceptance test, the suite's only
non-firing one: a machine must actually carry the commissioned floor,
since stored settings beat freshly baked defaults.
Three cloud cuts of one square at Precision Power 1, 100 and Full Power
show what the analog path is competing with: the power byte is pinned at
127 in all three, dose is FIRE-bit density on a fixed 7-tick period with
the on-count dithered between adjacent integers, and the power setting
never reaches the machine at all. Facts bank and item 17 carry the
numbers; CAMPAIGN-LOG carries both sessions.
rsyslog replaces busybox syslogd/klogd (VIRTUAL-RUNTIME_base-utils-syslog,
trimmed PACKAGECONFIG) and becomes the only log writer: the appended
/etc/rsyslog.conf sets the inputs and the ff_line format and includes
the per-logger rules that `forgectrl --render-syslog` renders from the
machine settings at boot. forgefirm-logrotate becomes forgefirm-logging:
render before rsyslog starts (S19), sweep the pre-syslog log files into
/data/forgefirm/legacy-logs once, and rotate the tree at boot and hourly
by rename + HUP instead of copytruncate. Pins bumped to the pushed
forgectrl (syslog emitter, Logs tab, export), grblHAL-glowforge (syslog
emitter) and python3-gfhardware apps (syslog handlers, capture dir);
the CI harnesses set FFLOG_STDERR=1 so failure diagnostics keep the
controller's log lines. BRINGUP carries the bench validation checklist
(Next work item 14); this is an image change and rides the next flash.
- LIGHTBURN.md: mandatory "Before you cut" safety section; the
walkthrough now reflects the firing machine (dry runs need the
layer output off or M5; live first-cut instructions); the homing
entry documents homing_mode and the gfcloud method; the machine
address is a placeholder.
- README.md: condensed safety section linking the full text and the
regulatory notes.
- INSTALL.md: "Regulatory and legal" section ahead of the install
steps; routine updates route through the panel updater rather than
the installer.
- BRINGUP.md: the release signing key is described as held offline
(no on-disk path); bench address and credential notes removed;
Next-work item 7 corrected (the installer embeds the production
release key); status entry for audit remediation Phases 0-1; the
GATE A kernel drills join the pending image-flash checklist.
- bench scripts: the target host comes from GF_HOST (or argv) instead
of a hardcoded address.
- laser_stream_test.py: per-session controller runs with a hermetic
cooling-verdict publisher; new assertions that every stream
terminates with FIRE clear (including M3 held to stream end) and
that no FIRE bit rides a zero-step gap; a cycle-churn session
exercises the stop/start seams.
Audit findings D-1, D-2, D-3, D-5, D-10, D-12, B-10, and the harness
half of D-4/G-1.
BRINGUP item 2: grbl-mode laser software implemented + bench-verified
without fire (record in the gate list); first light pending.
LIGHTBURN.md: arming/button-press operation, S-max 1000, fire gates.
scripts/bench/laser_stream_test.py: host-side stream-dump contract
verification against the null-sink build.
ScottW514