ColorCorrectOFX and similar plugins declare per-channel controls
(Gamma, Contrast, Saturation, Gain, Offset) as kOfxParamTypeRGBA.
Olive previously mapped every RGBA param to NodeValue::kColor and
rendered it as a ColorButton, which is semantically wrong for
adjustment sliders.
This commit adds heuristic semantic detection to distinguish
"true color" inputs (color pickers) from "per-channel scalar"
inputs (float sliders):
- label/hint/name keywords ("gamma", "contrast", "gain", ...)
- display range outside [0, 1]
- uniform default values across all channels
The detected semantic ("color" or "scalar") is stored as the
node input property "color_semantic". The display range and hint
are also persisted as "min" / "max" / "tooltip".
NodeParamViewWidgetBridge now branches on "color_semantic":
- "scalar" → 4× FloatSlider (reuses existing ProcessSlider /
keyframe-track logic, since kColor already splits into 4 tracks)
- otherwise → ColorButton (unchanged)
All 4 test suites pass.
Mike-Solar
b2de04962d