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_modes_p4.py

@@ -719,8 +719,10 @@ check("the forecast line names the forecast, what is counted and when",
       and "we count on" in sb["line"] and sb["state"] == "plan")
 why = homeview.day_key(c, B)
 check("B's Why key (plan, dark) is tops_up", why == "tops_up")
-check("...and says so in plain words", homeview.why_words(why)
-      == "Too little sun is forecast, so it charges some from the grid.")
+check("...and says so in plain words, with the level and what it covers "
+      "(OPT-28)", homeview.why_words(why, pct="82 %", kwh="9.4 kWh")
+      == "It charges from the grid to 82 %. That covers 9.4 kWh of "
+         "expensive hours the sun will not.")
 _d0, _d1 = homeview.local_day(c.solar_fc.at)
 _blocks, _ = homeview.mode_runs(c, _d0, _d1, c.solar_fc.at, False)
 _grid = [b for b in _blocks if b["kind"] == "grid" and b["battery"] == 1]
@@ -754,8 +756,8 @@ check("the Why line wins over 'saves its power' only while holding",
       == "grid_charge")
 for lang in ("en", "nl"):
     homeview._LANG[0] = lang
-    t = [homeview.why_words(k) for k in ("sun_fills", "tops_up",
-                                         "no_forecast")]
+    t = [homeview.why_words(k, pct="82 %", kwh="9.4 kWh")
+         for k in ("sun_fills", "tops_up", "no_forecast")]
     t += [homeview._t("solar.no_forecast"), homeview._t("solar.learning"),
           homeview.line_solar(9.2, 6.4, "10:15")]
     check(f"{lang}: every P4 sentence is there and short (<= 2 x 12 words)",