TARIFF-24 round 3: a run planned with a forecast keeps its gap to its end

Losing the solar forecast mid-run used to widen the gap at once and stop a
grid charge (and a sensor that went unavailable for a minute stopped and
restarted it). A run under way when the forecast is lost now keeps the gap it
was planned with until it ends (Controller.weather_held(), recorded by
_wx_track() each cycle a forecast is read); the wider gap applies from the next
run. The plan key holds the hold state so the plan rebuilds when it ends. Home's
mirror (homeview.trade_verdict) asks the same weather_held(now).

Tests: test_tariff24_weather.py part 4 (going: the charge continues to the run's
end, the next run is not_worth; flap of one and two reads: no stop, no restart;
Home agrees) and a test_modes_p4.py scenario that runs a forecast day at a gap
between 1x and 1.5x the cycle cost. DECISIONS wording follows.

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

goodwe_controller/test_modes_p4.py

@@ -614,6 +614,35 @@ check("sunny: a day plan is made, and says sunny",
           for r in rows))
 check("sunny: no grid charge at all", not charge)
 
+# TARIFF-24 round 2: the same day at the cycle cost 0.20 itself. With the
+# forecast read the gap needed is 0.20 (not 1.5 x = 0.30), so the midday
+# quarter 0.339 against the evening 0.551 (gap 0.21, between 1x and 1.5x) is
+# a planned top-up for B (Leftover solar) up to its planned level.
+rows_g, st_, c_g = run_day(SF_LS, fc=40.0, soc0={"a": 60.0, "b": 30.0})
+charge_g = invariants("gap between 1x and 1.5x", rows_g, c_g)
+_first_g = nth(charge_g, 0, "a charge cycle")
+_gaps = [min(g.mean_eur_kwh for g in r["runs"].give)
+         - r["runs"].cheap.mean_eur_kwh for r in charge_g
+         if r["runs"] is not None and r["runs"].give]
+print(f"    gap 0.20 <= gap < 0.30: {len(charge_g)} charge cycles, run gap "
+      f"{min(_gaps, default=0):.3f}, B to "
+      f"{max((r['soc']['b'] for r in rows_g), default=0):.1f} %")
+check("a forecast day whose price gap lies between 1x and 1.5x the cycle "
+      "cost (0.20 < 0.21 < 0.30) plans a cheap run: B charges from the grid "
+      "inside it, only B, and only up to its planned level",
+      present(_first_g) and len(_gaps) == len(charge_g)
+      and all(0.20 <= g < 0.30 for g in _gaps)
+      and all(r["runs"].cheap.holds(r["now"]) for r in charge_g)
+      and all(r["roles"][B] == modetrade.CHARGE for r in charge_g)
+      and all(r["roles"][A] != modetrade.CHARGE for r in charge_g)
+      and max(r["soc"]["b"] for r in rows_g) <= 45.64 + 2.0)
+check("...and the same day with no forecast read does not (it needs 0.30): "
+      "the old gate, kept for a day without a forecast",
+      not [r for r in run_day(SF_LS, fc=None,
+                              soc0={"a": 60.0, "b": 30.0})[0]
+           if r["action"] == arbitrage.CHARGE
+           and r["now"].astimezone(L).hour == 12])
+
 # Dark: 1 kWh. B buys the evening's shortfall only, in the cheap run.
 rows, st_, c = run_day(SF_LS, fc=1.0, soc0={"a": 60.0, "b": 30.0})
 charge = invariants("dark", rows, c)