Add Color Temperature Control via DDC

Summary

• Adds a new Color Temperature slider to MonitorControl that adjusts display warmth/coolness via DDC commands
• Implements color temperature by modulating Video Gain Red and Video Gain Blue DDC values
• Adds UI toggle in App Menu preferences to show/hide the Color Temperature slider
• Includes groundwork for per-display advanced settings for Color Temperature (DDC min/max overrides, curve, invert, remap)

How It Works

The color temperature control uses a simplified Kelvin-to-RGB approach:

• Slider at 0 (Cool/~9300K): Red gain = 40, Blue gain = 70
• Slider at 0.5 (Neutral/~6500K): Red gain = 50, Blue gain = 50
• Slider at 1 (Warm/~2700K): Red gain = 60, Blue gain = 30

This creates an asymmetric adjustment where blue changes more dramatically than red, mimicking real color temperature behavior.

Files Changed

Known Limitations

• Per-display advanced settings UI (DDC min/max, curve, invert, remap) for Color Temperature not yet wired in storyboard - IBOutlets are ready but UI elements need to be added in Interface Builder
• Color temperature uses Video Gain Red/Blue which may not be supported on all monitors