fix(light): fix color-temp out-of-range errors and migrate to ATTR_COLOR_TEMP_KELVIN

[ZakiZtraki]

Problem

Meross bulbs that support white/colour-temperature mode (e.g. MSL120D) return error code 5000 when Home Assistant sends a temperature payload outside the accepted range of 1–100:

Returned error: {'error': {'code': 5000, 'detail': 'Out of range.
  rgb value range: 0X0~0XFFFFFF, temperature range: 1~100, luminance range: 1~100'}}

The root causes were:

1. No clamping – the mired-to-Meross conversion (100 - norm_value * 100) produced negative values or values > 100 when the input fell outside the assumed min/max mired range.
2. Deprecated API – the code used ATTR_COLOR_TEMP (mired-based), which HA has deprecated and will remove in HA Core 2026.1, producing warnings in the log.
3. No explicit kelvin range – neither entity class declared _attr_min_color_temp_kelvin / _attr_max_color_temp_kelvin, so the HA UI slider used HA's broad defaults instead of the Meross-supported range.

Changes

• Migrate to ATTR_COLOR_TEMP_KELVIN in both LightEntityWrapper and DiffuserLightEntityWrapper, eliminating the HA 2026.1 deprecation warning.
• Simplify conversion – work directly in Kelvin (no mired inversion), mapping the device's 2700–6500 K range linearly to Meross's 1–100 scale.
• Clamp output with max(1, min(100, value)) as a safety net for edge-case inputs or floating-point drift.
• Declare kelvin range (_attr_min_color_temp_kelvin = 2700, _attr_max_color_temp_kelvin = 6500) on both entity classes so the HA slider stays within supported bounds.
• Replace color_temp with color_temp_kelvin on LightEntityWrapper to match the new API.

Compatibility

No existing configuration is broken:

• RGB and HS colour paths are untouched.
• Brightness/luminance path is untouched.
• The fix applies only to the colour-temperature conversion branch.
• The 2700–6500 K range covers all known Meross white-spectrum bulbs.

Tested devices

Model	Hardware	Firmware	White mode	Colour-temp slider	RGB mode
MSL120D	2.0.0	2.1.5	✅	✅ (no more Out of range errors)	✅

If you test this on additional devices, please comment below and I will update the table.