OPT-23, OPT-28: the day plan counts the sun right, and the night charge covers the expensive-hour shortfall

OPT-23: a state-only forecast is read from now for every span
(Forecast.between since=), so the plan's per-hour sun adds up to the day's
figure, today and tomorrow. Hourly splits are unchanged. The Forecast tab
reads spans the same way.

OPT-28: a Leftover solar battery buys, from the floor, the sum over the
expensive hours of max(0, house - trust x sun), / EFF. Several Leftover
solar batteries hold it together by capacity, the ceiling passes the rest
on, and what none can hold is said (Plan.uncovered_kwh). Home's grid block,
the Batteries line and the mode help (EN + NL) say the level, what it
covers, and that Leftover solar buys only what the sun will not give.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Bdqr7PiaHcBnzPituu2yTC

goodwe_controller/test_ux54.py

@@ -684,8 +684,9 @@ check("Dutch: the notes, the totals and the blocks are in Dutch, with a "
 c = S.make("dynamic", at(0, 18))
 nl_b = tab(c, at(0, 18), "nl")["days"][0]["batteries"][0]["blocks"]
 check("...and so are the plan's words on a block",
-      nl_b[0]["what"].startswith("Laadt tot") and nl_b[0]["why"].startswith(
-          "Goedkoopste uren") and nl_b[1]["what"].startswith("Levert tot"))
+      nl_b[0]["what"].startswith("Laadt maximaal") and " %" in nl_b[0]["what"]
+      and nl_b[0]["why"].startswith("Goedkoopste uren")
+      and nl_b[1]["what"].startswith("Levert tot"))
 check("the language goes back to English after a Dutch build",
       homeview.pill("running") == en["home_words"]["pill"]["running"])
 c = S.make("dynamic", at(10, 7))