SAFETY-125: a grid charge counts a late meter reading's seconds; the guard row says "over" when it is

A meter reading late near a quarter's end left seconds the projection did
not count (SAFETY-99), and charge_headroom_w() read them as room: the cheap
run (and price trading, and the N=2 maintenance charge) went back to full
power in the quarter's last seconds and the quarter could land over a banked
month peak or the cap. peakguard.charge_room_w() counts those seconds at the
held reading for the charge only; the guard's floor is unchanged.

The guard row said "idle, heading for 5 814 W, under this month's 5 413 W
peak". Over the limit at the current rate the row and the month-peak line
now say so, and that the grid charge is cut back.

Version 0.19.2, CHANGELOG, DECISIONS. test_safety125.py new; the lag pins
in test_price_run_fixes.py and test_opt20.py and the AST pin in
test_arbitrage.py follow the change (see the pull request).

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

goodwe_controller/test_arbitrage.py

@@ -936,6 +936,8 @@ def _s45_assigned(name, clear=("None",)):
 
 
 _s45_head_src = _s45_assigned("arb_headroom_w")
+# SAFETY-125: the guard's headroom with a late reading's seconds counted.
+S125_ROOM = "peakguard.charge_room_w(self.peak_guard, self._peak_proj)"
 print(f"    main.py has {len(_s45_calls)} `arbitrage.decide(` call site(s); "
       f"charge_headroom_w= is {_s45_arg}, and self.arb_headroom_w is assigned "
       f"from {_s45_head_src}")
@@ -944,7 +946,7 @@ check("main.py passes the guard's OWN measured headroom at its one "
       "transcription of it, so a mutation back to a literal or to max_w is red "
       "rather than silent",
       _s45_arg == ["self.arb_headroom_w"]
-      and _s45_head_src == ["peakguard.charge_headroom_w(self.peak_guard)"])
+      and _s45_head_src == [S125_ROOM])
 # ⚠️ AND THE HOIST DID NOT MOVE IT OUT OF THE CYCLE. An `arb_headroom_w` set
 # once in `__init__` and never refreshed would satisfy the pin above and would
 # size every trade from the guard decision of whatever cycle happened to run
@@ -960,8 +962,7 @@ check("...and the assignment is INSIDE the same `cycle()` that makes the call, "
       "and not one carried from an arbitrary earlier one",
       any(isinstance(n, ast.Assign)
           and [ast.unparse(t) for t in n.targets] == ["self.arb_headroom_w"]
-          and ast.unparse(n.value)
-          == "peakguard.charge_headroom_w(self.peak_guard)"
+          and ast.unparse(n.value) == S125_ROOM
           for n in ast.walk(_s45_cycle)))