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/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. |