Fan floors from the measurement; a hunt is measured, not judged

forgectrl pin 47e4256: the airflow floors set from the bench measurement
(exhaust 6400, intake 2290, air assist 6000 rpm, purge current 300, grace
15 s) and the operating-point rule: a fan is judged while the laser is
armed, when a job's profile may raise it but never lower it below the run
duty, or whenever it is commanded at the run duty; the service's hunts,
sent with the extraction fans off, are measured and published unjudged.

Catalog: cloud.mode-switch now waits out the connect-time hunt sampling
/cool/status and requires no AIRFLOW, the exhaust row unjudged and the
exhaust actually off; its covers gain forgectrl src/cool.* and
src/airflow.*. cooling.fan-gate-trips uses an 8 s test grace (the
intakes take 7 s to 90 percent and tripped under the old 2 s at the new
floor) and its off leg waits for the row state as well as gates_off.
fan_floor_measure.py names a reply that is not JSON and calls the purge
readings idle and run (the pump is always on).

Docs: COOLING 3a and the settings table, BRINGUP item 19 and a facts-bank
entry with the measured fan speeds, the bench README, and a CAMPAIGN-LOG
entry for the measurement, the two status-document finds, the hunt find
and the hot-deployed bench runs of both tests.

docs/BRINGUP.md

@@ -623,6 +623,18 @@ until `releases/v<version>/acceptance.json` is committed.
 
 ## Hardware facts bank (measured)
 
+- **Fan speeds at the cut profile** (exhaust duty 65535, intake 43278, air
+  assist 1023; sampled at 1 Hz over 120 s from idle, the exhaust duct's
+  inline booster fan off): exhaust **11640 rpm** steady (spread 11444 to
+  11947, 90 percent of steady in 5 s), intakes **4157 / 4158 rpm** (spread
+  under 100, 7 s), air assist **11050 rpm** (spread 30, 1 s); at idle the
+  exhaust and intakes read 0 / ~745 rpm and the air assist ~1900 rpm
+  (idle duty 204). The purge-air fan is always on and reads **~625 counts**
+  of `head/purge_air_current` (~1 when off). The airflow floors are 55
+  percent of these (bands 50 to 60 percent); an inline booster fan changes
+  the exhaust's back pressure and can move its reading by a few percent
+  either way, well inside the margin.
+
 - **DRV8825 stepper drivers wedge on 40 V rail glitches** (factory board; the
   TMC2130s belong to the upgraded OpenGlow board only). A glitch can leave the
   drivers unserviceable: SDMA playback and the position counters run normally
@@ -1340,13 +1352,18 @@ Open items only. Anything closed is in `CAMPAIGN-LOG.md`.
     while the run profile is applied (exhaust, intakes and air assist by
     tachometer, purge by current), a spin-up grace, three ticks under the
     floor, a fault for the rest of the session (`AIRFLOW`, no resume), a
-    header window only ever raising a floor; `cooling.fan-gate-trips` in
-    the catalog. The shipped floors are provisional, 55 percent of one
-    run-duty snapshot (exhaust 3700, intake 1800, air assist 6000 rpm,
-    purge current 300, grace 15 s) until `fan_floor_measure.py` has been
-    run on the bench and the numbers in `forgectrl/src/gates.c` set from
-    it. The coolant critical tier and the watch-only board temperatures
-    follow.
+    header window only ever raising a floor. A fan is judged at the
+    operating point its floor was measured at: always while armed (when a
+    job's profile may raise a fan but never lower it below the run duty),
+    and unarmed whenever it is commanded at the run duty; a cloud hunt,
+    sent with the extraction fans off, is measured and not judged.
+    `cooling.fan-gate-trips` and the hunt leg of `cloud.mode-switch` in
+    the catalog. The shipped floors are 55 percent of the bench machine's
+    measured steady speeds (facts bank: exhaust 6400, intake 2290, air
+    assist 6000 rpm, purge current 300, grace 15 s); the bench run of the
+    gate tests on an image carrying them, and the unplugged-tach drill,
+    are still owed. The coolant critical tier and the watch-only board
+    temperatures follow.
 
     Nothing here can put energy where it was not commanded: the hardware chain
     is the emission boundary and no header field touches it, and forgectrl runs

docs/CAMPAIGN-LOG.md

@@ -3254,6 +3254,60 @@ value), and the test quoted the session's first job-limits line, a hunt's,
 where the print's is the one worth keeping (it now takes the first line
 after the print's action request).
 
+## 2026-08-22: the fan floors measured, and a hunt that would have tripped them
+
+`fan_floor_measure.py spinup` (bench page `fan-floor`, 120 s at the cut
+profile from idle, GRBL mode, the exhaust duct's inline booster fan off, so
+the exhaust worked against more back pressure than a normal cut):
+
+| fan | steady rpm | min | max | sd | t90 |
+|---|---|---|---|---|---|
+| exhaust | 11638 | 11444 | 11947 | 103 | 5 s |
+| intake 1 | 4157 | 4102 | 4193 | 12 | 7 s |
+| intake 2 | 4158 | 4128 | 4173 | 6 | 7 s |
+| air assist | 11048 | 11029 | 11061 | 8 | 1 s |
+
+Purge current 627 at idle and 625 at run duty: the engine holds purge air on
+continuously, so both are the "on" reading (the off reading, ~1, is from an
+earlier observation). The floors shipped from this: exhaust 6400, intake
+2290, air assist 6000 rpm (55 percent of steady, bands 50 to 60 percent),
+purge current 300, grace 15 s (twice the slowest time to 90 percent). The
+provisional floors had come from a snapshot at a lower exhaust speed; the
+measured margin is larger.
+
+The run also sent the first `/cool/status` with the limits and the fan rows
+through a 512-byte reply buffer, and then a 160-byte limits fragment: twice
+a cut-off document, found by the measurement tool refusing to parse it.
+Both fixed in forgectrl with a host test that renders the widest legal
+document and parses it (`tests/coolfmt_test.c`).
+
+Reading the measurement through cloud mode found a defect in the gates as
+first built: the service reports every action as a run, and its hunt and
+motion headers command the exhaust and the intakes off and the air assist
+at idle, so a hunt longer than the grace would have tripped `AIRFLOW` at
+any floor. Decision (operator): a fan is judged only at the operating
+point its floor was measured at: always while the laser is armed, when a
+job's profile may raise a fan but never lower it below the run duty; and
+unarmed when commanded at the run duty. A hunt is measured, published as
+`unjudged`, and not judged. `cloud.mode-switch` now watches the connect-time
+hunt's gate rows for it.
+
+Both tests ran the same day on a hot-deployed forgectrl (the working tree
+cross-built and installed over dev image `20260821230723`; informational,
+not acceptance). `cloud.mode-switch` PASS: the hunt reported two run ticks
+with the exhaust off and `unjudged`, verdict `OK` throughout.
+`cooling.fan-gate-trips` FAIL first, for two reasons worth keeping: the
+run-start tick resolved the effective limits before it reloaded the
+settings, so for one tick `gates_off` named the exhaust while its row still
+carried the old floor (fixed: the session start re-resolves the limits after
+the reload, so rows, `gates_off` and the log line agree); and the test's
+2 s grace, chosen against the provisional 1800 rpm intake floor, now let
+both intakes trip at ~1850 rpm on their 7 s spin-up (the test grace is 8 s).
+Rerun PASS in 59 s: only the exhaust tripped in the exhaust leg, only the
+purge in the purge leg, the exhaust read `off` with floor 0 in the off leg,
+and the restore showed every fan `ok` at the shipped floors (exhaust 11723,
+intakes 4157 and 4162, air assist 11078 rpm, purge 628 counts).
+
 ## Superseded status notes
 
 ### Shared machine services — remaining polish, as listed 2026-08-13

docs/COOLING.md

@@ -145,9 +145,20 @@ floor.
 
 - **The floors** are settings (§8): `cool_tach_exhaust_min_rpm`,
   `cool_tach_intake_min_rpm` (either intake), `cool_tach_air_assist_min_rpm`
-  and `cool_purge_min_current`, each a fraction of what the fan reaches at
-  run duty on the bench machine. A cloud job's header can raise a tach floor
-  for that job, never lower it (§2).
+  and `cool_purge_min_current`, each 55 percent of the steady speed the fan
+  reaches at the cut profile on the bench machine (exhaust 11640, intakes
+  4160, air assist 11050 rpm; the recommended bands are 50 to 60 percent).
+  A cloud job's header can raise a tach floor for that job, never lower it
+  (§2).
+- **A fan is judged at the operating point its floor was measured at.**
+  While the laser is armed every fan is judged, and a job's own fan profile
+  (a cloud header's run duties) may raise a fan above the cut profile but
+  never lower it while armed. Unarmed, a fan is judged whenever it is
+  commanded at or above the cut profile (a bare `M8` from a GRBL job), and a
+  fan the job runs slower is measured, published as `unjudged`, and not
+  judged: the factory's hunts and homing moves run with the exhaust and the
+  intakes off and the air assist at idle, and nothing can fire during them.
+  The purge fan has no duty (it is always on) and is judged in every run.
 - **A spin-up grace** (`cool_fan_grace_s`) runs from the moment the run
   profile is written; nothing counts inside it, because the big exhaust fan
   takes seconds to reach speed.
@@ -164,7 +175,8 @@ floor.
   reading in a job that would have tripped the shipped default is logged.
 
 `/cool/status` carries each fan's reading, floor and state (`grace`, `ok`,
-`under`, `TRIPPED`, `off`, or `idle` outside a run) as `fan_gates`.
+`under`, `TRIPPED`, `off`, `unjudged` for a fan the job runs below the cut
+profile unarmed, or `idle` outside a run) as `fan_gates`.
 
 ---
 
@@ -355,9 +367,9 @@ start of every run, so a change takes effect on your next job.
 | `cool_temp_resume` | 31 °C | 5 to 59 °C | 20 to 36 °C | Resume gate: below it, continue. Always kept below the ceiling. |
 | `cool_cooldown_s` | 15 s | 0 to 1800 s | | Smoke-clear phase at run duty after a job. |
 | `cool_cooldown_max_s` | 300 s | 0 to 1800 s | | Cap on the thermal cooldown phase. |
-| `cool_tach_exhaust_min_rpm` | 3700 rpm | 0 to 20000 | 2500 to 5000 | Exhaust fan floor at run duty (§3a). `0` turns the gate off. |
-| `cool_tach_intake_min_rpm` | 1800 rpm | 0 to 20000 | 1200 to 2500 | Intake fan floor, either intake (§3a). `0` turns the gate off. |
-| `cool_tach_air_assist_min_rpm` | 6000 rpm | 0 to 30000 | 4000 to 8000 | Air-assist fan floor (§3a). `0` turns the gate off. |
+| `cool_tach_exhaust_min_rpm` | 6400 rpm | 0 to 20000 | 5800 to 7000 | Exhaust fan floor at run duty (§3a). `0` turns the gate off. |
+| `cool_tach_intake_min_rpm` | 2290 rpm | 0 to 20000 | 2100 to 2500 | Intake fan floor, either intake (§3a). `0` turns the gate off. |
+| `cool_tach_air_assist_min_rpm` | 6000 rpm | 0 to 30000 | 5500 to 6600 | Air-assist fan floor (§3a). `0` turns the gate off. |
 | `cool_purge_min_current` | 300 raw | 0 to 1023 | 150 to 500 | Purge-air fan current floor (the fan has no tachometer; about 1 off, about 630 on). `0` turns the gate off. |
 | `cool_fan_grace_s` | 15 s | 0 to 120 s | 5 to 30 s | Spin-up window after the run profile is written, during which no floor counts. |