Add support for cold water (KW01) cost type

[Svetlinski1985]

My Munich portal (nutzerportal.brunata-muenchen.de) meters heating (HZ01) and cold water (KW01), but not hot water. The integration only creates sensors for HZ01 — no entities are generated for KW01, even though the data is available in the portal.
Evidence that KW01 exists

The dashboard_perioden sensor lists both cost types for every period:

periods:

• from: /Date(1767225600000)/
  to: /Date(1785456000000)/
  cost_types:
  • HZ01
  • KW01

... same for all older periods

All generated sensors, however, only carry cost_type: HZ01.

Expected behavior:
Sensors should be created for every cost type returned by the portal, including KW01 (cold water), analogous to the existing HZ01 / WW01 handling. Cold water is typically reported in m³ rather than kWh.

Notes:
The underlying brunata-nutzerportal-api ReadingKind enum appears to define only heating and hot_water; a cold_water / KW kind may need to be added there as well.
Environment
Portal: Munich (nutzerportal.brunata-muenchen.de, SAP client 201)

[Svetlinski1985]

Update – root cause identified and KW01 successfully tested

I was able to investigate this further and can confirm that the Brunata backend does provide the cold-water data for KW01.

A direct call using the existing brunata-nutzerportal-api already works:

await client.get_monthly_consumption(
cost_type="KW01",
in_kwh=False,
period_index=0,
)

This returns the monthly cold-water consumption correctly in m³. I compared the returned values with the official Brunata app and they match.

Example values:

2026-01: 12.35 m³
2026-02: 10.71 m³
2026-03: 11.67 m³
2026-04: 13.92 m³
2026-05: 14.02 m³
2026-06: 15.48 m³
2026-07: 7.12 m³

The cumulative values also correspond to the Brunata app (e.g. 23.06 m³ after February and ~85.26 m³ after July).

So the problem does not appear to be that the SAP backend does not expose KW01. The main issue seems to be the current cost-type discovery/mapping:

get_monthly_consumption(cost_type="KW01", in_kwh=False) works already.

get_monthly_consumptions() only discovers HZ* for ReadingKind.heating or WW* for ReadingKind.hot_water.

get_meter_readings() explicitly filters cost types to ("HZ", "WW").

get_consumption_comparison() and get_consumption_forecast() also only include HZ/WW and currently query with InKwh=true.

ReadingKind currently has only heating and hot_water, so a direct KW01 result is internally classified as hot_water.

I tested a local modification of the HA integration which adds KW01 separately with InKwh=false. This is working successfully and now exposes cold-water sensors in Home Assistant in m³, including monthly consumption and cumulative water consumption. Meter reading, YTD/forecast/comparison data can also be requested for KW01 using the corresponding dashboard endpoints with InKwh=false.

From my testing, a proper implementation would therefore probably require:

adding a cold_water reading kind / KW mapping,

including KW* cost types in cost-type discovery,

querying KW values with InKwh=false,

exposing them as Home Assistant SensorDeviceClass.WATER in m³,

keeping KW values separate from the existing synthetic kWh statistics.

I can provide the working changes to coordinator.py / sensor.py if helpful.