SAFETY-52 review: a refusal is under 100 W, and any delivery ends it

- Engage (and seed from a stale stop) below REFUSED_BELOW_W, the probe's
  own 100 W answer, not below saturation_w: a battery derated to 100-499 W
  was held at 0 W ~93 % of the time.
- A reading of 100 W or more in the held direction ends the refusal, probe
  or not: at a 1 s meter SETTLE_CYCLES is 12 s, shorter than a healthy
  reading's lag, and that held a healthy step at 0 W until the next probe.
- test_refusal part 5b and a seed test; DOCS states the N>1 limit; the
  DECISIONS record carries the traced cause of the replay's extra trips.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

goodwe_controller/app/control.py

@@ -286,6 +286,10 @@ REFUSED = "battery refuses"
 PROBING = "battery probe"
 PROBE_W = 200.0
 PROBE_ANSWER_W = PROBE_W / 2
+# "Gives nothing" is below the probe's own answer, not below `saturation_w`: a
+# pack derated to 100-499 W is a limit, and at 500 W it kept ~7 % of its power
+# (review of #141). The capture's refusals read -4 W.
+REFUSED_BELOW_W = PROBE_ANSWER_W
 PROBE_EVERY_S = 900.0
 PROBE_S = 34.0
 
@@ -773,18 +777,19 @@ def compute(
 
     # --- SAFETY-52: a refused direction is held at 0 W ----------------------
     # Engages only where the freeze has held for SETTLE_CYCLES and the unit
-    # delivers ~nothing: a reading within `saturation_w` of 0 against an ask
-    # beyond it is a refusal, not a slow plant. The drop to 0 skips the slew
+    # delivers ~nothing: a reading below REFUSED_BELOW_W against an ask beyond
+    # `saturation_w` is a refusal, not a slow plant. The drop to 0 skips the slew
     # limit because it only removes an ask the battery is not meeting.
     if refused is not None:
         if (refused == 0 and frozen and sat_count >= SETTLE_CYCLES
                 and abs(prev_w) > tuning.saturation_w
-                and abs(actual_w) < tuning.saturation_w):
+                and abs(actual_w) < REFUSED_BELOW_W):
             refused = 1 if prev_w > 0 else -1
         if refused and refused * i_w < 0:
             refused = 0                          # the loop wants the other way
-        elif refused and probe and refused * actual_w >= PROBE_ANSWER_W:
-            refused = 0                          # the probe was answered
+        elif refused and refused * actual_w >= PROBE_ANSWER_W:
+            refused = 0                          # it delivers: a probe answered,
+            #                                     or a slow reading arriving
         elif refused:
             wants = refused * i_w > 0
             i_w = 0.0