Fetches GET /api/prices?start&end&zone (15-min slots, EUR/MWh) and stores
the raw market price as feed_in_tariff_wh (EUR/Wh) — no import charges/VAT.
Slots beyond the day-ahead horizon are left to the consumer's forward-fill
(FeedInTariffImport behaviour).
5 unit tests + opt-in live smoke (EOS_DVHUB_ONLINE_LIVE=1, passing).
Signed-off-by: Christin <info@bikinibottom.capital>
Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>
