v0.4.1

A correctness fix to the surplus calculation, plus its observability. No breaking changes.

Fixed

• The load-compensated surplus is now sun-aware: below PV_SUN_MIN_ELEVATION_DEG
  (default 3°) the compensation is disabled, so the heat pump is released after dark instead
  of being held ON on grid power. Previously the fixed + wp_nominal compensation could keep
  the SG-Ready relay ON past sunset (observed: relay still on at ~00:00 with the WP idle).

Added

• PV_SUN_MIN_ELEVATION_DEG (default 3.0) to tune the elevation gate.
• Gauge surplus_control_sun_elevation_deg; the UI "why" card shows "Sun below the horizon"
  when idle after dark.

[0.4.0] - 2026-06-16

Generic, vendor-neutral heat-pump telemetry. Breaking: the ViCare-specific service, DB table
and metric names are replaced by a generic contract behind a pluggable driver.

Changed

• vicare-exporter → heatpump-exporter with a HEATPUMP_DRIVER (vicare | mock) behind
  a HeatPumpDriver protocol — the heat-pump analogue of METER_DRIVER. ViCare is now one
  driver; a mock driver renders the heat-pump card in the zero-config demo.
• DB table heatpump_vicare → heatpump_telemetry (migration 003, data preserved).
• Prometheus telemetry metrics vicare_* → heatpump_* (vendor-API ops stay vicare_*).
• control-ui is vendor-neutral; the heat-pump card name comes from HEATPUMP_LABEL.

Added

• docs/heatpump-interface.md — the generic telemetry contract + "bring your own driver".

Upgrade

• Apply migration 003 (the compose db-migrate one-shot does this automatically).
• Switch the image vicare-exporter:0.3.x → heatpump-exporter:0.4.0 with HEATPUMP_DRIVER=vicare
  (keep your existing VICARE_* secrets).
• Update any custom Grafana panels / external scrapers from vicare_*/heatpump_vicare to
  heatpump_*/heatpump_telemetry. Set HEATPUMP_LABEL (e.g. Vitocal 250 A06).