SAFETY-41: correct the comment, and fix the check it cites

Review found two false statements in the comment and one weak check. All
three are fixed here; the constant itself is unchanged at 150 s and was
never in question.

1. "That caps this constant at 900/5 = 180 s" was FALSE ABOUT THE CHECK IT
   CITED. test_clamp.py part 2 sweeps i = 0..899 and the rising edge at
   i=0 is free, so it measured `1 + floor(899/R)` - one alarm more than a
   real quarter earns. Measured: 224 s was GREEN across the whole suite.
   Anyone raising this to 200 s would have had a green board and a
   requirement quietly unmet - the same defect recorded at
   test_clamp.py:216, one notch weaker.

   The check now grades floor(QUARTER_S / REASSERT_S) directly, so it
   enforces the ceiling the comment claims for it. Verified: 150 PASS,
   180 PASS, 181 FAIL, 224 FAIL. 180 is also the true requirement edge -
   on the worst sliding 900 s window 180 earns 5 alarms and 181 earns 4.

2. The "60 cycles of the §10.3 runaway" note was attributed to this module
   and truncated. It is main.py:2479 and reads "60 cycles of the §10.3
   runaway produce 0 write-path engagements and 2 loop-side ones". Quoted
   in full, attributed correctly.

3. "48 engagements in 25 minutes" was left implying a pinned rail. It is
   roughly one cycle in six - real, and far above the 2-in-60 the guard
   was sized for, but not continuous. Restated, and labelled as a live-log
   reading rather than a measurement in this repo.

Also recorded: the 1500 W tuning derivation is in the OTHER repo
(admin/goodwe NOTES.md, "Simulated 2 kW load step (gain 0.6, clamp
1500)"), so this repo cannot corroborate it and a reader should not go
looking here; and MIN_PER_QUARTER = 5 is a test-local integer, not a spec
figure - the 900 s quarter is system-wide but the 5 is not, so the 180 s
ceiling rests on one number a test author chose.

Full suite: 20 passed, 0 failed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU

goodwe_controller/test_clamp.py

@@ -239,6 +239,21 @@ print(f"    pinned on the rail for {QUARTER_S:.0f} s at 1 s cycles: "
 check(f"a loop pinned for a whole billing quarter speaks at least "
       f"{MIN_PER_QUARTER} times (it spoke {alarms})",
       alarms >= MIN_PER_QUARTER)
+# ⚠️ REVIEW-FOUND, SAFETY-41, and it is the SAME DEFECT as the one recorded
+# twenty lines above, one notch weaker. The sweep above runs i = 0..899 and the
+# rising edge at i=0 is FREE, so it measures `1 + floor(899 / REASSERT_S)` - one
+# alarm more than a real quarter earns. Measured on this very check:
+#   REASSERT_S = 180 -> 5 alarms, green   (and 180 is the true edge: on the worst
+#   REASSERT_S = 224 -> 5 alarms, GREEN    sliding 900 s window 180 gives 5 and
+#   REASSERT_S = 225 -> 4 alarms, red      181 gives 4)
+# So the check as written permits 224 s while the REQUIREMENT permits 180 s, and
+# anyone raising the constant to 200 s would get a green suite and conclude the
+# floor was met when a real quarter would earn 4 alarms. Grade the cadence
+# DIRECTLY, so the check enforces the ceiling its own comment claims for it.
+check(f"...and the CADENCE itself honours the floor, independent of where the "
+      f"sweep happens to start: floor({QUARTER_S:.0f}/{REASSERT_S:.0f}) = "
+      f"{int(QUARTER_S // REASSERT_S)} >= {MIN_PER_QUARTER}",
+      QUARTER_S // REASSERT_S >= MIN_PER_QUARTER)
 check(f"...and on no more than {MAX_FRACTION:.0%} of cycles (it was "
       f"{alarms / QUARTER_S:.1%})", alarms <= MAX_FRACTION * QUARTER_S)
 check("...while every single cycle is still counted",