Tibber's API `total` already includes the buy-side inkoopvergoeding
(verified from production data: total = spot×1.21 + energy_tax 0.11085 +
inkoopvergoeding 0.0248). Under net metering Tibber pays back
`total − verkoopvergoeding` per returned kWh (NL: EUR 0.28 -> 0.2552), so the
two EUR 0.0248 fees do NOT cancel — the feed-in price sits 0.0248 below buy.
Model the verkoopvergoeding as a first-class, always-subtracted contract
field `energy.sell_fee` (default 0.0248) instead of folding it into
`sell_adjust`. New sell formula:
sell = total − energy_tax − sell_fee − sell_adjust
`sell_adjust` now carries only the net-metering energy-tax refund
(= −energy_tax). Applied in both the billing strategy and the /prices
endpoint; recorded in the pricing snapshot. Frontend renders the field
automatically (dynamic profile form). Docs (references, m6) corrected to
drop the wrong "fees cancel" premise.
- routes/api/energy.py + schemas/energy.py: GET prices (tibber points or manual
tariff, buy/sell consistent with the pricing strategies), GET costs (time
window + limit, ascending), GET costs/summary (summarize passthrough), GET
dsmr/latest, POST costs/recompute (idempotent, <=366d guard, CSRF), POST
tibber/test (three-state, token never echoed, CSRF).
- main.py registers router; OpenAPI re-exported; tests for all endpoints.
tliu93