The cheap run is sized at the full rating, so under the peak limit a battery is
still short when it ends, and control plans the next run then. Home drew only
the run under way. `cheaproll` rolls the run on the way control does
(`modetrade.energy()` + `priceruns.plan()` at each run end, lifted from
`dayview._levels()`), reading the levels at the charge power the peak limit
leaves (peak aim less the house, else the rating). `homeview.mode_runs()` and
`price_windows()` use it for today: the grid block, the Today line and the
chart's cheap bars run to where control stops, each battery's block to its
own stop. Display only: no control change.
test_ux54: today's grid block of the night-before scenario now follows the roll.
Co-Authored-By: Claude <noreply@anthropic.com>