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/app/main.py

@@ -960,6 +960,9 @@ class Controller:
         # and whether last tick filed a mode trade (a run edge reseeds).
         self.mode_runs = None
         self._runs_key = None
+        # TARIFF-24: the end of the run that was under way while a forecast
+        # was read; until then losing the forecast does not widen the gap.
+        self._wx_free_to = None
         self.mode_tick = None
         self._run_done = {}
         self._mode_trade_was = False
@@ -2226,6 +2229,28 @@ class Controller:
                 probing=probing))
         return out
 
+    def _wx_track(self, now) -> None:
+        """TARIFF-24, once per cycle, before the plan: with a forecast read,
+        remember when the run now under way (cheap, give or sell) ends."""
+        if self.solar_fc is None:
+            return
+        rp = self.mode_runs
+        ends = []
+        if rp is not None and rp.on:
+            ends = [r.end for r in (rp.cheap, rp.sell)
+                    if r is not None and r.holds(now)]
+            g = rp.give_at(now)
+            if g is not None:
+                ends.append(g.end)
+        self._wx_free_to = max(ends) if ends else None
+
+    def weather_held(self, now) -> bool:
+        """TARIFF-24: no forecast now, but a run planned with one is under
+        way: it keeps its gap to its end. The wider gap applies from the next
+        run. Pure; Home asks the same (`homeview.trade_verdict()`)."""
+        return (self.solar_fc is None and self._wx_free_to is not None
+                and now < self._wx_free_to)
+
     def _price_runs(self, now, packs, floor_pct, ceiling_pct):
         """The kept run plan, rebuilt at most once per price slot (15 min) or
         when the prices or a battery's choice change; a run under way is
@@ -2239,9 +2264,11 @@ class Controller:
         slot = int(now.timestamp() // 900)
         key = (id(plan), slot, tuple((p.name, p.use, p.mode, p.sell)
                                      for p in packs))
+        held = self.weather_held(now)
         if self.fc_entity is not None:
-            # P4: a forecast arriving or going rebuilds the plan at once.
-            key += (self.solar_fc is None,)
+            # P4: a forecast arriving or going rebuilds the plan at once (and
+            # so does the end of a run that held the gap, TARIFF-24).
+            key += (self.solar_fc is None, held)
         if key != self._runs_key:
             done_c = self._run_done.get("charge", (None, set()))[1]
             done_s = self._run_done.get("sell", (None, set()))[1]
@@ -2250,7 +2277,7 @@ class Controller:
             required = price_required_spread(
                 arbitrage.threshold_eur_kwh(self.o),
                 price_uncertainty_of(plan.read.product)
-                | arbitrage.weather_uncertainty(True, self.solar_fc))
+                | arbitrage.weather_uncertainty(True, self.solar_fc, held))
             ref = self._ref_cheap
             if ref is not None and now - ref.end > REF_CHEAP_KEEP:
                 ref = self._ref_cheap = None
@@ -2319,6 +2346,7 @@ class Controller:
         quarter), exactly the gate `arbitrage.decide()` has."""
         floor_pct, ceiling_pct = arbitrage.soc_bounds(self.o)
         packs = self._mode_packs(maint_results)
+        self._wx_track(now)
         runs = self._price_runs(now, packs, floor_pct, ceiling_pct)
         guard = arbitrage.guard_state(self.peak_guard)
         plan = self.fresh_tariff_plan(now)
@@ -2329,7 +2357,8 @@ class Controller:
             return plan.arbitrage(
                 peak_guard_active=active,
                 min_spread_eur_kwh=arbitrage.threshold_eur_kwh(self.o),
-                uncertainty=arbitrage.weather_uncertainty(True, self.solar_fc),
+                uncertainty=arbitrage.weather_uncertainty(
+                    True, self.solar_fc, self.weather_held(now)),
                 now=now).match(
                     allowed=lambda _v: True, refused=lambda _v: False)
         if guard is not None and plan is not None and runs is not None: