OPT-15: price-run fixes (quarter edge, charge-end overshoot, refusal probe)

F1: with battery modes on, the peak guard projects the quarter `now` is in
even before its first P1 sample (PeakTracker.project(roll=True)), and only
a measured stop latches the period. The edge tick no longer reads "no
seconds left", so a charge is not stopped and latched at a quarter edge.

F2: after a run edge the loop is held at E until the meter shows the step
(EDGE_HOLD_S, longer while the battery still moves). The replay gained a
lag model (dead time, reading age, P1 debounce, 1 s cycles) that shows
TEST-23's overshoot without the hold.

F3: a charge refuser's SAFETY-73 probe inside a cheap run is a charger
pinned at PROBE_W, the others rest, so the probe actually runs.

Modes off stays byte-identical to 5a4cdc2 (new late-P1 identity scenarios).

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

goodwe_controller/app/modetrade.py

@@ -21,17 +21,17 @@ Roles (the page's Why line names them):
            grid the others cannot give power either; the allocator never
            splits a target both ways).
 
-Rules that keep this safe (tests: test_modes_p3.py):
+Rules that keep this safe (tests: test_modes_p3.py, test_price_run_fixes.py):
   * every range holds 0 W (a mode may forbid a direction, never force one);
   * a Solar first battery never charges from the grid (no forecast yet, P4);
   * grid charging needs a measured peak guard that is clear and a measured
     headroom (SAFETY-45); the trade is sized to that headroom, whose aim is
     `peak_cap_w - peak_margin_w` (SAFETY-79). It starts only at START_W or
-    more, and once the guard or the headroom stops it, it stays stopped for
-    the rest of that 15-minute period (`blocked`): a charge makes the other
-    batteries stop giving power, so a few watts of charge flipping on and
-    off would swing the house between them and the grid (measured on the
-    2026-09-09 replay: 13 flips in 4 minutes at a 3.5 kW house);
+    more, and once the guard or a measured headroom stops it, it stays
+    stopped for the rest of that 15-minute period (`blocked`): a charge
+    makes the other batteries stop giving power, so a few watts of charge
+    flipping on and off would swing the house between them and the grid
+    (measured on the 2026-09-09 replay: 13 flips in 4 minutes at 3.5 kW);
   * selling needs selling on for that battery, the sell run, a price >= 0
     now, and the battery above `arbitrage_soc_floor`; it stops there. The
     peak guard never stops a sell (section 9.1: discharge is never capped);
@@ -39,7 +39,10 @@ Rules that keep this safe (tests: test_modes_p3.py):
   * a battery out of a run (full, or at the floor) stays out until the run
     ends, so the ceiling and the floor do not re-arm within one run;
   * a battery that refuses a direction (SAFETY-52/73) takes no part in a
-    run in that direction: the refusal wins over the run.
+    run in that direction: the refusal wins over the run. The one exception
+    is its SAFETY-73 probe inside a cheap run (OPT-15): it is a charger then,
+    pinned at PROBE_W by its own claim, so the others rest (one sign) and the
+    card's "tries again every 15 minutes" holds in the run too.
 """
 
 from dataclasses import dataclass
@@ -69,6 +72,7 @@ class Pack:
     live: bool = True
     idle: bool = True           # not in a maintenance phase
     refused: int = 0            # SAFETY-52/73: +1 refuses to give, -1 to charge
+    probing: bool = False       # OPT-15: its SAFETY-73 probe window is open
 
 
 @dataclass(frozen=True)
@@ -88,13 +92,16 @@ def _room_kwh(p: Pack, pct: float) -> float:
     return max(0.0, abs(pct - p.soc)) / 100.0 * float(p.capacity_kwh)
 
 
-def chargers(packs, ceiling_pct, done=()) -> list:
+def chargers(packs, ceiling_pct, done=(), probe=False) -> list:
     """Batteries that may charge from the grid in a cheap run: the modes in
-    `packmode.GRID_CHARGE_MODES` (Cheap hours only until P4's forecast)."""
+    `packmode.GRID_CHARGE_MODES` (Cheap hours only until P4's forecast).
+    With `probe`, also one refusing to charge while its SAFETY-73 probe is
+    open: its own P_SAFETY pin keeps it at PROBE_W (OPT-15)."""
     return [p for p in packs
             if p.use and p.idle and p.live and p.mode in GRID_CHARGE_MODES
             and p.soc is not None and p.soc < ceiling_pct
-            and p.refused >= 0 and p.name not in done]
+            and (p.refused >= 0 or (probe and p.probing))
+            and p.name not in done]
 
 
 def sellers(packs, floor_pct, done=()) -> list:
@@ -137,7 +144,8 @@ def decide(runs, now, packs, *, charge_ok, sell_ok, trade_why, price_now,
     in_sell = plan_on and runs.sell is not None and runs.sell.holds(now)
 
     why = None
-    ch = chargers(packs, ceiling_pct, done_charge) if in_cheap else []
+    ch = chargers(packs, ceiling_pct, done_charge, probe=True) \
+        if in_cheap else []
     charging = False
     if ch:
         need = 0.0 if charging_now else START_W