OPT-11 P1 review: a mode never beats the peak floor; SAFETY-03 kept at the rail

- arbiter: a mode now gives way only as far as a site limit above P_MODE
  needs (_unit_modes at N>1, _site_mode at N=1). Before, the modes were
  released only when the peak floor bound S, so a trade won above the floor
  kept them and placed less than the floor (an Off battery at N=1 went to 0 W
  under a 2000 W floor), and a capped grid charge released an Off battery.
  While released, held batteries weigh 0 and carry only the shortfall.
- control: a side of the loop bound that reaches the rail is left to the
  rail, so SAFETY-03's i_clamped still fires with every battery on.
- opt11_identity: add maintenance scenarios and a 6000-case arbiter digest
  (peak floor, trades, maintenance, refusals); a5dddad digests pinned.
- tests: test_arbiter part 11, test_control (g), test_modes (0/1 refused,
  loop bound counts live units only). DOCS and DECISIONS say the new rule.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UBtqPrG1mDLXzTEBnhEkkV

goodwe_controller/app/control.py

@@ -17,6 +17,7 @@ exists because its absence produced a specific, observed failure.
 """
 
 import math
+from math import inf
 from dataclasses import dataclass
 
 # ---------------------------------------------------------------------------
@@ -500,6 +501,14 @@ def compute(
     # main.py never builds one: every term of `loop_bound()` holds 0).
     if bound is not None and not (bound[0] <= 0.0 <= bound[1]):
         bound = None
+    # ...and a side of it that reaches the rail is left to the rail, so that
+    # SAFETY-03's `i_clamped` still fires when the loop winds into it. With
+    # every battery on, the bound IS the rail, and the law is exactly as it was.
+    if bound is not None:
+        _rail = min(tuning.max_w, tuning.max_w if tuning.integrator_max_w is None
+                    else tuning.integrator_max_w)
+        bound = (float(bound[0]) if bound[0] > -_rail else -inf,
+                 float(bound[1]) if bound[1] < _rail else inf)
 
     # --- saturation, WITH the duration term -------------------------------
     # Command and actual diverging means the inverter cannot follow - it is at
@@ -603,9 +612,8 @@ def compute(
             i_w = max(moved, i_w)
 
     # OPT-11: the integrator does not wind past what the modes let the
-    # batteries place. Applied BEFORE the integrator bound below, so a loop
-    # held by a mode reads as `mode-bound` and not as SAFETY-03's winding into
-    # the rail (`i_clamped`). That bound still bites where it is the tighter.
+    # batteries place. Only a side tighter than the rail is left in `bound`
+    # (above), so this never takes SAFETY-03's `i_clamped` away from the rail.
     if bound is not None:
         held = max(float(bound[0]), min(float(bound[1]), i_w))
         if held != i_w: