forgetest: witness the airflow behind the beam; harnesses carry the armed flag

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.

forgetest/forgetest/suite/laser.py

@@ -90,6 +90,7 @@ def sample(ctx):
         "ir": st.get("lid_ir"),
         "homed": st.get("homed"),
         "armed": cs.get("armed"),
+        "phase": cs.get("phase"),
         "fire_watch": cs.get("fire_watch"),
         "verdict": cs.get("verdict"),
         "beam": hw.sysfs_int("head/beam_detect_analog"),
@@ -110,8 +111,13 @@ def sample(ctx):
     }
 
 
-TRAIL_FIELDS = ("t", "gstate", "kstate", "emission", "armed", "il", "button_latch", "locked",
+TRAIL_FIELDS = ("t", "gstate", "kstate", "emission", "armed", "phase", "il", "button_latch",
-                "lid", "button", "hv_enable", "beam", "hv", "msgs")
+                "locked", "lid", "button", "hv_enable", "beam", "hv", "msgs")
+
+# The cooling phases that run the fans at their idle duty: the engine has
+# no run session, so no cut airflow and no flow interrogation. Emission
+# in one of these is the beam on the work with idle airflow.
+IDLE_AIRFLOW_PHASES = ("idle", "warm-up")
 
 
 def trail(samples):
@@ -465,9 +471,17 @@ def emission_witness(ctx):
                 for i in range(4):
                     ir_peak[i] = max(ir_peak[i], s["ir"][i])
         armed_seen = any(s["armed"] for s in samples)
+        # The beam may only come on inside a run session. Until the engine
+        # has taken the armed window it is still holding the fans at their
+        # idle duty, and the verdict standing on file is the one it
+        # computed for the idle session before the arm.
+        idle_fire = [s for s in samples
+                     if s["emission"] and s["phase"] in IDLE_AIRFLOW_PHASES]
         ev.update({"samples": len(samples), "emission_peak": peak, "emission_end": end,
                    "hv_min": min(hv) if hv else None, "hv_max": max(hv) if hv else None,
                    "lid_ir_peak": ir_peak, "armed_seen": armed_seen,
+                   "idle_airflow_fire": [(round(s["t"] - samples[0]["t"], 2),
+                                          s["phase"], s["emission"]) for s in idle_fire],
                    "pgood_peak": max((s["pgood"] for s in samples if s["pgood"] is not None), default=None)})
         ctx.log("emission_samples peak=%s end=%s; hv %s..%s; lid_ir peak %s; armed seen %s",
                 peak, end, ev["hv_min"], ev["hv_max"], ir_peak, armed_seen)
@@ -488,6 +502,11 @@ def emission_witness(ctx):
         ctx.log("time-to-disarm after Idle: %s s", ev["disarm_after_idle_s"])
     ctx.check(armed_seen, "the armed window was never observed (arm refused, or no button press)")
     ctx.check(peak > 0, "no emission witnessed (emission_samples stayed 0)")
+    first_idle_fire = ev["idle_airflow_fire"][0] if idle_fire else (None, None, None)
+    ctx.check(not idle_fire,
+              "the laser fired while the cooling engine had no run session, so the fans were at "
+              "their idle duty (phase %s at t=%s s, emission %s)",
+              first_idle_fire[1], first_idle_fire[0], first_idle_fire[2])
     ctx.check(end == 0, "emission_samples did not return to 0 at Idle (%s)", end)
     ctx.check(hv and max(hv) > min(hv), "HV current did not rise during the burn (%s..%s)",
               ev["hv_min"], ev["hv_max"])

scripts/bench/laser_stream_test.py

@@ -375,10 +375,13 @@ def wait_state(sock, log, prefix, timeout=5.0):
 def publish_verdicts(path, stop):
     """Publish a fresh, clean cooling verdict every 0.5 s (the arm flow
     refuses without one; freshness window is 2 s). Same-host monotonic
-    clock, atomic rename so the reader never sees a torn file."""
+    clock, atomic rename so the reader never sees a torn file. "armed"
+    is the engine's acknowledgment that it has taken the controller's
+    armed window; the arm waits for it, so a stand-in engine that means
+    to let jobs run must assert it."""
     while not stop.is_set():
         body = ('{"ts_mono":%.3f,"fire_ok":true,"hold":false,'
-                '"resume_ok":true,"reason":""}'
+                '"resume_ok":true,"armed":true,"reason":""}'
                 % time.clock_gettime(time.CLOCK_MONOTONIC))
         tmp = path + ".tmp"
         with open(tmp, "w") as f: