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_opt34.py

@@ -186,9 +186,9 @@ check("a fresh figure replaces the kept one at once (04:00: 5.0 today, "
       and fy.today.kwh == 5.0 and fy.tomorrow.kwh == 9.0)
 fy2 = rs(st(5.0, at(4, 7, 55)), GONE, at(4, 8, 0), hd)[0]
 check("... and at 08:00, today fresh and tomorrow's sensor down for over 3 h: "
-      "tomorrow is the 03:50 figure for the 5th (9.0, kept: OPT-38), never "
+      "tomorrow is the 03:50 figure for the 5th (9.0, not flagged kept before 20:00: OPT-38), never "
       "the 3rd's 12.0", fy2 is not None and fy2.today.kwh == 5.0
-      and fy2.tomorrow is not None and fy2.tomorrow.kwh == 9.0 and fy2.kept)
+      and fy2.tomorrow is not None and fy2.tomorrow.kwh == 9.0 and not fy2.kept)
 
 # Restart: the saved hold keeps the figure.
 for label, now in (("01:00", at(4, 1, 0)), ("04:00", at(4, 4, 0))):