OPT-38 round 2: a kept tomorrow reading is flagged kept only from 20:00

Before the bell ends it replaced today's Home line and the event log with
the kept-for-tonight wording. stand_in() docstring covers the tomorrow case.

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

goodwe_controller/test_opt27.py

@@ -146,7 +146,7 @@ for label, tm in (("stale", st(12.0, at(4, 9, 5))), ("unavailable", GONE)):
     check(f"14:00, today fresh, tomorrow {label} since 09:05 (over 3 h): "
           "the 09:05 figure covers it, kept (OPT-38: at any hour)",
           fd is not None and fd.tomorrow is not None
-          and fd.tomorrow.kwh == 12.0 and fd.kept)
+          and fd.tomorrow.kwh == 12.0 and not fd.kept)
     fn = rs(st(0.1, at(4, 20, 55)), tm, at(4, 21, 0), h9)[0]
     check(f"21:00, tomorrow {label}: the 09:05 figure covers it, kept",
           fn is not None and fn.tomorrow is not None