OPT-27: test_modes_p4 says what a covered sensor does; test_opt27 guards

test_modes_p4.py: 'the forecast is lost mid-run' now loses it for good (a hold
that never covers); a second scenario is the same loss with the hold, which
keeps Leftover solar charging. test_opt27.py: a failing check no longer hides
the ones after it.

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

goodwe_controller/test_modes_p4.py

@@ -672,9 +672,24 @@ check("Cheap hours with a sun forecast charges as with none (P3)",
       and top > 80.0)
 
 # The forecast goes away mid-run: Leftover solar stops at once (P3 option A).
+# OPT-27: a sensor that is unavailable is covered by its last fresh reading
+# for up to 3 h (`solarfc.Hold`), so "lost" here is a hold that never covers;
+# the next scenario is the same loss with the hold (test_opt27.py).
 DROP = UTC0 + timedelta(hours=1, minutes=30)
+
+
+class _NoHold(solarfc.Hold):
+    def stand_in(self, *a, **k):
+        return None
+
+
+def seed_profile_no_hold(c):
+    seed_profile(c)
+    c.fc_hold = _NoHold()
+
+
 rows, st_, c = run_day(SF_LS, fc=lambda now: 1.0 if now < DROP else None,
-                       soc0={"a": 60.0, "b": 10.0})
+                       soc0={"a": 60.0, "b": 10.0}, patch=seed_profile_no_hold)
 invariants("forecast lost mid-run", rows, c)
 before = [r for r in rows if r["now"] < DROP and r["action"]
           == arbitrage.CHARGE]
@@ -682,6 +697,15 @@ late = [r for r in rows if r["now"] > DROP + timedelta(
     seconds=2 * 60 + 10) and r["action"] == arbitrage.CHARGE]
 check("forecast lost mid-run: Leftover solar was charging, and stops within "
       "a forecast read (60 s) and a cycle", before and not late)
+rows, st_, c = run_day(SF_LS, fc=lambda now: 1.0 if now < DROP else None,
+                       soc0={"a": 60.0, "b": 10.0})
+invariants("forecast unavailable mid-run, covered", rows, c)
+check("forecast unavailable mid-run (OPT-27): the last reading covers it, so "
+      "Leftover solar goes on charging past the point where it was lost",
+      [r for r in rows if r["now"] < DROP and r["action"]
+       == arbitrage.CHARGE]
+      and [r for r in rows if r["now"] > DROP + timedelta(
+          seconds=2 * 60 + 10) and r["action"] == arbitrage.CHARGE])
 
 # The forecast is far too high (40 kWh, and there is no sun at all): no grid
 # charge, so B covers less of the evening - a money risk, never a safety one.