Fix temperature unit conversion for Fahrenheit display

[Pinkcommando]

Summary

Fixes temperature display when Home Assistant is configured to use Fahrenheit. Previously, the component displayed
Celsius values with the °F symbol, causing confusion for users in Fahrenheit-using regions.

Relevant issue: #1042

Changes

• Added automatic temperature unit conversion based on Home Assistant's configured unit
• Auto-detects device temperature unit from JSON (Celsius or Fahrenheit)
• Devices with minTemperature > 40 are inferred as Fahrenheit (e.g., General Electric models)
• Future device files can explicitly specify "temperatureUnit": "°F" or "°C"

Implementation Details

• Device temperatures (min/max/target from JSON) are stored in the device's native unit
• Display temperatures are converted to Home Assistant's configured unit
• User input is converted back to device unit before sending IR commands
• Temperature sensor readings remain unconverted (already in HA's configured unit)

Supported Scenarios

Device Unit	HA Config	Behavior
Celsius	Celsius	No conversion (existing behavior)
Celsius	Fahrenheit	Converts C → F for display
Fahrenheit	Fahrenheit	No conversion
Fahrenheit	Celsius	Converts F → C for display

[adouglass]

When testing this change, I've noticed that restarting Home Assistant results in the initial set temperature of my climate entities to be unrealistically high (e.g. 167 degrees Fahrenheit).

My device uses code 2100 which has a minTemperature of 17 (Celsius). My Home Assistant is running in Imperial units.

[Pinkcommando]

When testing this change, I've noticed that restarting Home Assistant results in the initial set temperature of my climate entities to be unrealistically high (e.g. 167 degrees Fahrenheit).

My device uses code 2100 which has a minTemperature of 17 (Celsius). My Home Assistant is running in Imperial units.

I pushed a potential fix for your issue, please let me know if this solves your problem.

[adouglass]

This fixes the issue I had found when HA starts and restores the previous state