SAFETY-40: the integrator bound is not a BUG SIGNAL; numbers from the clamp tick

The clamp alarm gave `i_clamped` (normal anti-windup) the over-rating BUG
SIGNAL text, printed `Decision.i_w` as "the loop asked for", and printed
`self.target` (after slew/freeze) as "was clamped to".

- clamp.loop_clamp_note(): i_clamped says "the loop's integrator reached its
  N W anti-windup bound" with this tick's command; clamped keeps BUG SIGNAL
  with the requested command and the clamp's own result.
- Decision carries i_bound_w / requested_w / clamped_w, set at the clamp.
- i_clamped still counts and notifies (same id, cadence, SAFETY-41
  escalation) but as a WARNING, amber row, plain title. A bug has its own
  notification budget and its text is not overwritten within an episode.
- test_clamp.py part 9: red on the old code per defect; 5 mutations killed.
- DOCS.md alarm section (and its stale 30 s cadence), DECISIONS/SAFETY-40.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LyR88rXETvwhTgx6yHE39p

goodwe_controller/app/clamp.py

@@ -73,6 +73,7 @@ An alarm wired only to this module's `ClampResult.engaged` would therefore be
 silent on the exact configuration the whole ticket is about. The winding is
 visible one layer up, at the integrator bound, and that is why `Decision` now
 carries `i_clamped` / `clamped` BOOLEANS and the caller ORs them in here.
+They alarm in different words: see `loop_clamp_note()` (SAFETY-40).
 
 AND WHY BOOLEANS RATHER THAN `Decision.reason`. `reason` is a single string that
 later stages overwrite: a cycle that clamps the integrator and is then slew
@@ -200,9 +201,8 @@ REASON_CODE = "OUTPUT_CLAMP"
 # ceiling rests on one number a test author chose; if that number is ever
 # revisited, this constant moves with it.
 #
-# ⚠️ THIS IS A STOP-GAP AND DOES NOT MAKE THE ALARM CORRECT. The message still
-# calls the integrator bound a BUG SIGNAL and still pairs a request from one
-# moment with a `self.target` read at another - SAFETY-40. Nothing here is
+# ⚠️ THIS WAS A STOP-GAP; the wording and the numbers were SAFETY-40's, fixed
+# in `loop_clamp_note()` below. Nothing here is
 # suppressed: every engagement is still counted, the action-log row is written on
 # every engaged cycle regardless, and the rising edge of every episode alarms
 # unconditionally, so no alarm is DROPPED - only delayed.
@@ -234,6 +234,31 @@ CLEAR_CYCLES = 3
 SUSTAINED_CYCLES = 3
 
 
+BUG_SIGNAL = ("This is a BUG SIGNAL, not a limit being used: something "
+              "upstream computed a setpoint the actuator cannot deliver.")
+
+
+def loop_clamp_note(d) -> str:
+    """The loop-side alarm text for one `control.Decision`, or "".
+
+    SAFETY-40: the integrator bound is anti-windup doing its job and says so;
+    only a command over the rating is a BUG SIGNAL. Every number is the
+    decision's own, i.e. from the tick that clamped.
+    """
+    if d.clamped:
+        return (f"{REASON_CODE}: the loop computed {d.requested_w:+.0f} W, over "
+                f"the {abs(d.clamped_w):.0f} W rating, and it was clamped to "
+                f"{d.clamped_w:+.0f} W; the loop's command this cycle was "
+                f"{d.target_w:+.0f} W. {BUG_SIGNAL}")
+    if d.i_clamped:
+        return (f"{REASON_CODE}: the loop's integrator reached its "
+                f"{d.i_bound_w:+.0f} W anti-windup bound; the loop's command "
+                f"this cycle was {d.target_w:+.0f} W. Brief "
+                f"engagements after a large load or solar step are normal. If it "
+                f"persists, check that the battery is following its commands.")
+    return ""
+
+
 @dataclass(frozen=True)
 class ClampResult:
     """What the guard did, with the RAW value preserved.
@@ -342,23 +367,51 @@ class ClampWatchdog:
         # spoken yet - the two the escalation clause needs.
         self.run_len = 0
         self.spoken = False
+        # SAFETY-40. Did this episode include a genuine over-rating (`bug`), and
+        # has THAT spoken? A bug has its own budget, so anti-windup notices can
+        # never delay it; with bug=True throughout, cadence is as before.
+        self.bug = False
+        self.bug_spoken = False
+        self.last_bug_alarm: datetime | None = None
 
-    def note(self, engaged: bool, reason: str, now: datetime) -> bool:
+    def _due(self, last, now) -> bool:
+        return last is None or (now - last).total_seconds() >= REASSERT_S
+
+    def _speak(self, now, bug) -> bool:
+        self.last_alarm = now
+        self.spoken = True
+        if bug:
+            self.last_bug_alarm = now
+            self.bug_spoken = True
+        return True
+
+    def note(self, engaged: bool, reason: str, now: datetime,
+             bug: bool = True) -> bool:
         """Advance one cycle. True when the caller should raise the alarm.
 
         `now` is the caller's clock, the same discipline as
-        `SignWatchdog.evaluate()` and `FreezeWatchdog.evaluate()`.
+        `SignWatchdog.evaluate()` and `FreezeWatchdog.evaluate()`. `bug` False
+        is the integrator bound (SAFETY-40): counted and notified like the
+        rest, but it never replaces a bug's text within an episode.
         """
         if engaged:
             self.engagements += 1
             self.clean_cycles = 0
-            self.reason = reason
             self.run_len += 1
-            if not self.active:
+            rising = not self.active
+            if rising:
                 self.active = True
                 self.since = now
                 self.episodes += 1
                 self.spoken = False
+                self.bug = False
+                self.bug_spoken = False
+            if bug or not self.bug:
+                self.reason = reason
+            self.bug = self.bug or bug
+            if bug and not self.bug_spoken and self._due(self.last_bug_alarm, now):
+                return self._speak(now, True)
+            if rising:
                 # ⚠️ SAFETY-41. THE RISING EDGE IS RATE-LIMITED TOO, and it did
                 # not used to be. It fired unconditionally, so a condition that
                 # engages and clears repeatedly raised one notification PER
@@ -384,11 +437,8 @@ class ClampWatchdog:
                 # still written on every engaged cycle, and a genuine runaway -
                 # which by definition keeps engaging - is picked up by the
                 # re-assert path within REASSERT_S. Delay, not loss.
-                if (self.last_alarm is None
-                        or (now - self.last_alarm).total_seconds() >= REASSERT_S):
-                    self.last_alarm = now
-                    self.spoken = True
-                    return True
+                if self._due(self.last_alarm, now):
+                    return self._speak(now, self.bug)
                 return False
             # ⚠️ THE ESCALATION. An episode that has not yet spoken because the
             # budget was spent by an EARLIER, unrelated episode speaks anyway
@@ -396,15 +446,10 @@ class ClampWatchdog:
             # engages every cycle and reaches it; the scattered one-cycle
             # railing that produced the live flood never does.
             if not self.spoken and self.run_len >= SUSTAINED_CYCLES:
-                self.last_alarm = now
-                self.spoken = True
-                return True
+                return self._speak(now, self.bug)
             # Still engaged: re-assert on the slow cadence, not every cycle.
-            if (self.last_alarm is None
-                    or (now - self.last_alarm).total_seconds() >= REASSERT_S):
-                self.last_alarm = now
-                self.spoken = True
-                return True
+            if self._due(self.last_alarm, now):
+                return self._speak(now, self.bug)
             return False
 
         self.run_len = 0
@@ -420,5 +465,6 @@ class ClampWatchdog:
             # above. The episode ends; the notification budget does not reset
             # with it.
             self.reason = ""
+            self.bug = False
             self.clean_cycles = 0
         return False