Replace the weconnect library with carconnectivity and
carconnectivity-connector-volkswagen. The connector is configured via
a dict passed to CarConnectivity(); startup()/fetch_all() replace
login()/update(). All domain extractors in data_model.py are rewritten
for the new object model (vehicle.charging.*, vehicle.get_electric_drive(),
vehicle.climatization.*, etc.). Remaining time fields are now derived
from estimated_date_reached DateAttributes. Battery temperatures are
read directly in °C (no Kelvin conversion). Auth error handling drops
the manual re-login since the connector manages token refresh internally.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>