v0.1.2

scheduler: spill late/missed windows into tomorrow, extend active period mid-charge

Recompute now always plans today + tomorrow, so a late plug-in or all-too-expensive
hours don't produce an empty schedule. During an active session, the running
period can grow into adjacent recomputed hours instead of being cut short, and
elapsed periods with no overlapping session log a missed_period event.

Also: meter poller now handles counter resets via a persisted offset, and the
price chart clamps negative consumption to zero.