SAFETY-85 review: grade discharge only, over the plant's settle time

Rule 2 graded each battery against last cycle's command and graded charges
too. On plantsim's battery (10 s lag) at the 2 s meter it warned at every
drain or charge start and 15 times an hour under the peak guard at N=2; a
charge tapering near full warned 11 times in 50 min (SAFETY-42 section 7).
Now a discharge is graded against the least it stood at over SHORT_CYCLES /
SHORT_SPAN_S. DOCS lists `mode-bound` under Loop reason. test_safety85 part 7:
peak guard with a dead battery, lagging plant, taper; part 3: the bound ends
with maintenance.

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

goodwe_controller/DECISIONS/SAFETY-85-no-false-not-keeping-up.md

@@ -25,14 +25,16 @@ counter counted cycles (861), not episodes.
    the loop. Its number is on the wire, or only a rating (`device`,
    `supervised`) cut it. No bound held it, and nothing was unmet.
    (`Controller._loop_alarm_input`.)
-2. **A battery another owner set alarms when it gives less than it was told.**
-   This covers every battery on a cycle the loop did not decide, and a battery
-   with its own pin otherwise. The test is more than `saturation_w` short in
-   the told direction, for `saturation_cycles` cycles in a row, against what
-   stands on the wire (`clamp.delivery_short`). It covers a real shortfall
-   during maintenance. Before, that shortfall was silent unless the kick
-   happened to reach the rail (house 1000 W, drain 2000 W, battery gives
-   nothing: 0 warnings before, 4 in 10 min now).
+2. **A battery another owner set to discharge alarms when it gives less than
+   it was told.** This covers every battery on a cycle the loop did not
+   decide, and a battery with its own pin otherwise. The test is more than
+   `saturation_w` short of the least it stood at over `SHORT_CYCLES` cycles
+   and `SHORT_SPAN_S` (the plant's measured settle, SAFETY-13/73), for
+   `saturation_cycles` cycles in a row (`clamp.delivery_short`). It covers a
+   real shortfall during maintenance or under the peak guard. Before, that
+   shortfall was silent unless the kick happened to reach the rail (house
+   1000 W, drain 2000 W, battery gives nothing: 0 warnings before, 4 in 10 min
+   now).
 3. **At N>=2, while maintenance holds a battery, the loop is bounded** by
    OPT-11's `loop_bound()` (what the batteries may place). It does not wind,
    and control comes back one slew step a cycle. Why maintenance only: that is
@@ -69,12 +71,21 @@ batteries can give. The `alarmed()` helpers in test_safety84/86 also read
 SAFETY-81's quarter stamp, because ALLOCATOR rows can push its row out of
 the 40-row log.
 
+**Review (PR #163).** The first draft graded each battery against last
+cycle's command and graded charges too. On plantsim's battery (10 s lag) at
+the live 2 s meter, every drain or charge start warned once, and an N=2 drain
+or HOLD under the peak guard with a stepping house warned 15 times an hour. A
+maintenance charge tapering near full warned 11 times in 50 min, which
+SAFETY-42 section 7 had ruled out. With the settle window and discharge only:
+0 in all of those cases. A battery that gives nothing still warns, lagging
+or not. At a hypothetical 20 s lag, it warns at most twice an hour. The cost:
+a battery that does not take a charge another owner set is not named by this
+alarm (the same gap SAFETY-42 states; the charge has its 36 h timeout).
+`test_safety85.py` part 7.
+
 **Not changed, open for the owner.**
 - With the loop in charge and the house above the batteries' total rating,
   it still warns (SAFETY-40). On the rig's 2 x 2000 W N=2, most of SAFETY-84's
   count came from houses of 4500 and 6500 W.
-- A battery that tapers near full during a charge, more than `saturation_w`
-  under its command for 15 s, now warns (rule 2). The text already says
-  "check it is not empty or full".
-- TEL-10's `loop_reason` reads `mode-bound` while the maintenance bound holds
-  the loop, with modes off.
+- TEL-10's `Loop reason` reads `mode-bound` while the maintenance bound holds
+  the loop, with modes off. DOCS lists the value with both meanings.