OPT-36 round 3: B's charge counts the cheap time left; OPT-34 nights on their own shapes

The run is sized at the batteries' ratings, not the peak limit, so a run too
short to fill a Cheap hours battery is planned again later in the night.
Counting that run alone made B's give grow through the night and A's level
fall after A had bought (round 2: 55 -> 69 -> 41 -> 37 %, A to 56 %).
dayplan._cheap_give_kwh() now also counts the later firm slots before the
expensive hours that a run would still be worth charging in (price + the
spread control asks at most the give run's dearest slot); the Controller
passes the slots and the spread.

test_opt34: back to the original house shapes, fixture and expected values.
B is Off in the nights that test A's level (a Cheap hours B now covers
these hours); B's checks run in new `_b` nights; the 03:00 check runs in a
night from midnight; tail starts A at 60 %; late_fresh reads the kept 6.0.
test_opt36: slot cases, a whole night on one figure (level never moves),
F-1 with B counted (raised level reached and held). test_ux54: the run end
is read from the plan and asserted (02:30); the F1/F2 sweep uses a peak
limit that does not bind and reads a level shown as the target as at it.

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

goodwe_controller/DOCS.md

@@ -549,7 +549,7 @@ With battery modes on, these choices replace the *Charging and selling on price*
 - The hourly shape is kept only if every sensor has one. Otherwise the total is spread over the day as for Forecast.Solar.
 - Before each cheap run the add-on asks: will the sun fill the batteries before the expensive hours? It counts on `solar_trust_pct` of the forecast (70 %), less what the house uses. Solar first batteries get that sun first.
 - *Leftover solar* then charges from the grid only the shortfall: for each expensive hour, what the house uses less the sun counted for that hour (never below 0), added up over all the expensive hours, early morning and evening. With a day and night tariff that is 07:00 to 22:00. Not up to the top level.
-- All *Leftover solar* batteries hold that shortfall together, shared by their size. A battery that reaches the top level passes the rest to the others. If all of them together cannot hold it, they all fill to the top level. *Cheap hours only* and *Solar first* batteries give first: what they will hold when the expensive hours start (a *Cheap hours only* battery full, or as far as its cheap run reaches under the peak limit; a *Solar first* battery after the night's use) is taken off the shortfall. In the expensive hours the rest comes from the grid. The Batteries screen says so. The sun before the expensive hours still fills first, and is taken off what is bought.
+- All *Leftover solar* batteries hold that shortfall together, shared by their size. A battery that reaches the top level passes the rest to the others. If all of them together cannot hold it, they all fill to the top level. *Cheap hours only* and *Solar first* batteries give first: what they will hold when the expensive hours start (a *Cheap hours only* battery full, or as far as it can charge under the peak limit in the cheap hours left; a *Solar first* battery after the night's use) is taken off the shortfall. In the expensive hours the rest comes from the grid. The Batteries screen says so. The sun before the expensive hours still fills first, and is taken off what is bought.
 - A forecast that gives only one figure for the day (Forecast.Solar) is spread over the hours from now, so the hours add up to that figure.
 - *Cheap hours only* ignores the forecast and fills to the top level.
 - *Solar first* never charges from the grid.