Fix invalid device_class + unit_of_measurement combinations for HA 2026.5

HA 2026.5 enforces strict validation of device_class/unit_of_measurement
pairs in MQTT discovery payloads. Four categories were broken:

- power_factor: unit was sent as "power_factor" (the FIMP field name); HA
  requires the field to be omitted or empty for this device class. Fixed by
  normalising the display unit separately from the FIMP data-path key.

- illuminance: unit "Lux" is rejected; normalise to "lx". When a sensor
  reports luminance as "%" (some Z-Wave devices), the illuminance device
  class is dropped so the entity becomes a generic sensor rather than
  triggering a validation error.

- reactive_power (regular/export meter): unit "VAr" is rejected; HA requires
  lowercase "var".

- reactive_power (extended meter values, e.g. p_import_react): the unit
  determination logic fell through to the generic power branch and sent "W";
  reactive power extended values now emit "var", apparent power values emit
  "VA", and reactive energy values emit "kvarh".

Fixes #31

futurehome/CHANGELOG.md

@@ -1,9 +1,5 @@
 <!-- https://developers.home-assistant.io/docs/add-ons/presentation#keeping-a-changelog -->
 
-## 1.6.2 (16.05.2026)
-
-- Fix invalid device_class + unit_of_measurement combinations for HA 2026.5 (#32).
-
 ## 1.6.1 (16.10.2025)
 
 - Tweaked 'Ignore Availability Reports' setting.

futurehome/config.yaml

@@ -1,6 +1,6 @@
 # https://developers.home-assistant.io/docs/add-ons/configuration#add-on-config
 name: Futurehome
-version: '1.6.2'
+version: '1.6.1'
 slug: futurehome
 description: Local Futurehome Smarthub integration
 url: 'https://github.com/adrianjagielak/home-assistant-futurehome'