cooling.fan-gate-trips: a fan under its floor is a fault; pin the airflow gates

The acceptance catalog gains the test behind forgectrl 5a31d66: an
exhaust floor at the legal maximum must trip AIRFLOW after the grace and
three ticks (hold, fire blocked, no resume, the exhaust gate TRIPPED and
named in the reason); a purge current floor at the ADC rail must trip
the same way; an exhaust floor of zero must read off in gates_off and
trip nothing; restored, the next session must run OK with every fan at
or above its floor. Three host cases against a scripted engine that
models the grace and the readings. The covers map names src/airflow.*.

COOLING.md gains 3a (the airflow gates) and the five settings with their
ranges and bands; SERVICES.md the gate rule, the rows, the AIRFLOW
verdict and fan_gates; SAFETY.md names the floors among the verdict's
inputs; BRINGUP item 19 records the gates as in with provisional floors
and the catalog at 44. Pins: forgectrl 5a31d66, forgefirm-app 81027ff
(0.1.15+git); fetch-verified.

meta-forgefirm/recipes-forgefirm/forgectrl/forgectrl-pin.inc

@@ -2,5 +2,5 @@
 # only SRCREV and PV here - the image manifest leaves *-pin.inc out of the
 # layer content hash because the component entry already identifies the
 # pinned source (forgefirm-image-manifest.bbclass).
-SRCREV = "e0b41b33ee13c29d0ff772b15a919b2b24bfa24b"
+SRCREV = "5a31d66e15f299daff540d0ca49e67b893fa841d"
 PV = "0.1.0"

meta-forgefirm/recipes-forgefirm/forgefirm-app/forgefirm-app-pin.inc

@@ -4,9 +4,9 @@
 # because the component entry already identifies the pinned source
 # (forgefirm-image-manifest.bbclass). The python3-gfhardware recipe in
 # meta-glowforge-bsp pins the same repository; move both together.
-SRCREV = "c34faa1402d09c888ab8f7eccdf26dd8ec4be405"
+SRCREV = "81027ffc3617c092e0fa23005d599229ebe57d61"
 
 # Bump PV with every SRCREV move: the hash-derived package version is not
 # monotonic on its own and buildhistory QA fails the build when it sorts
 # backwards.
-PV = "0.1.14+git"
+PV = "0.1.15+git"