OPT-27: the night plan keeps the last fresh solar forecast

Forecast.Solar's sensors stop updating in the evening, so at night every such
site had no forecast: the night cheap run needed 1.5x the cycle cost and
Leftover solar planned nothing. One missed poll also dropped it at once.

solarfc.Hold keeps the last fresh reading of each sensor, for the day it is
for. A missing or stale sensor is covered by it for up to FRESH_S (a short
outage), and from the end of the bell (20:00) until local midnight + 3 h
however old. A tomorrow figure is tomorrow's until midnight and then today's;
a today figure is only today's. Stored in the controller's store
(solar_fc_hold), so an evening restart keeps it. The forecast line says
'Solar forecast read 17:05, used for tonight's plan.' (EN, NL).

test_tariff24_weather.py runs with a hold that never covers: it tests what the
plan does when the forecast IS lost.

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

goodwe_controller/test_tariff24_weather.py

@@ -43,7 +43,7 @@ logging.disable(logging.WARNING)
 import opt11p3_replay as rp                                    # noqa: E402
 from named_absence import first, nth, present                  # noqa: E402
 import app.main as m                                           # noqa: E402
-from app import arbitrage, homeview, modetrade                 # noqa: E402
+from app import arbitrage, homeview, modetrade, solarfc        # noqa: E402
 from app.main import Controller                                # noqa: E402
 from app.p1 import make_sample, split_signed                   # noqa: E402
 from app.price import (PricePoint, PriceProduct, PriceRead,    # noqa: E402
@@ -54,6 +54,13 @@ from app.store import unit_key                                 # noqa: E402
 fails = []
 
 
+class _NoHold(solarfc.Hold):
+    """OPT-27: a hold that never stands in for a lost sensor."""
+
+    def stand_in(self, *a, **k):
+        return None
+
+
 def check(name, cond):
     print(f"  {'ok  ' if cond else 'FAIL'} {name}")
     if not cond:
@@ -157,6 +164,11 @@ def drive(o, *, fc="fresh", points=None, minutes=20, tick=5.0,
         for i in c.inverters:
             i.dev_min, i.dev_max = -5000.0, 5000.0
         c.auto = True
+        # OPT-27: a sensor that is missing is covered for up to 3 h by its last
+        # fresh reading. This file is about what the plan does when the
+        # forecast IS lost, so it runs with a hold that never covers
+        # (test_opt27.py tests the cover).
+        c.fc_hold = _NoHold()
         real_dt, real_hv = m.datetime, homeview.datetime
         clock = [NIGHT]