Per-device color calibration with assisted 3D-LUT wizard

[joaocaparroz]

Per-device color calibration with assisted 3D-LUT wizard

Closes #293

Summary

Makes RGB devices from different models look the same by extending per-device calibration into an optional color pipeline, plus an assisted wizard that matches a target device to a reference device by eye.

Motivation

The same logical color renders slightly differently across devices. The existing DeviceCalibrations (one multiplicative SimpleColor per device) can only dim each channel — it can't fix non-linear brightness response, the tonality of mixed colors (white matches but purple doesn't), or specific stubborn colors.

What's added

• Calibration model (DeviceCalibration): per-channel brightness CalibrationCurve, a 3×3 ColorMatrix, an optional non-linear set of ColorSamples baked into a 3D-LUT, plus the existing manual brightness/gamma/gain.
• Runtime apply (CalibrationLookup): curve → matrix → 3D-LUT (trilinear) → manual, resolved once per device update and cached. Applied for all device types — RGB.NET (per sub-device in RgbNetDeviceUpdater) and native (centrally in DefaultDevice).
• Assisted wizard (Control_CalibrationWizard): pick a reference + target device; stage 1 matches per-channel brightness, stage 2 fits the matrix from white + primaries + secondaries, stage 3 fixes specific intermediate colors (suggested list + add-your-own). Devices are lit to live test colors over the device-manager pipe (calibrationPreview / calibrationEnd).
• Indicators in the calibration window: a status badge (3D-LUT · N pts · Matrix · Curves · Manual), a before/after hue preview, and a Details panel showing the matrix and the LUT correction points.

Backward compatibility

Legacy DeviceCalibrations (SimpleColor) are migrated into the new model on config load (DeviceConfig.MigrateCalibrations); the new data lives in DeviceColorCalibrations.

Scope / limitations

• The assisted preview (lighting both devices) targets RGB.NET devices; native devices still get the runtime apply + manual sliders.
• The matrix is a linear approximation; the optional 3D-LUT covers the non-linear cases.
• No automated tests added — the repo has no test project; the color-matrix fit was validated by reasoning (identity in → identity out, scalar in → scalar matrix) and the runtime paths exercised live.

How to test

1. Settings → Device Manager → Calibrate Devices.
2. Adjust the per-device sliders, or click Assisted Calibration… and follow the stages.
3. Verify the badge/preview/Details reflect the active calibration, and that devices visually match.

Screenshots