Rewrite as Surplus Pilot: one plan for car, home battery and devices (v3.0.0)

Surplus Load Switch (devices) and Smart Car Charger (EV) ran side by side and
fought over the same surplus: the charger left the battery less because it
knew the car would leave before sunset, the device controller didn't know
that, saw the battery "behind schedule" and reserved everything for it, so
devices got a budget of zero while plenty of PV was forecast.

Surplus Pilot replaces both with a single pure planner (planner.py):
car obligation for the next departure -> home battery (departure-aware) ->
devices by priority -> car top-up, with the top-up moved before the devices
when the car gets no PV chance tomorrow, and a late, cheapest-slot grid
fallback when PV can't reach a departure target. Replayed on 30 days of
recorded data the same code cut feed-in by 21 % and raised device runtime
without missing a departure target.

Vendor-neutral: every input is a free entity choice (car control on the car
or the wallbox, any price sensor, any Energy-dashboard solar forecast).
New domain surplus_pilot; no automatic migration from surplus_load_switch.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: xchillxx

.gitignore

@@ -3,3 +3,6 @@ __pycache__/
 .DS_Store
 .vscode/
 .idea/
+__pycache__/
+*.pyc
+.pytest_cache/