* CURVE node
* remove curve to sigmas node
* feat: add CurveInput ABC with MonotoneCubicCurve implementation (#12986)
CurveInput is an abstract base class so future curve representations
(bezier, LUT-based, analytical functions) can be added without breaking
downstream nodes that type-check against CurveInput.
MonotoneCubicCurve is the concrete implementation that:
- Mirrors frontend createMonotoneInterpolator (curveUtils.ts) exactly
- Pre-computes slopes as numpy arrays at construction time
- Provides vectorised interp_array() using numpy for batch evaluation
- interp() for single-value evaluation
- to_lut() for generating lookup tables
CurveEditor node wraps raw widget points in MonotoneCubicCurve.
* linear curve
* refactor: move CurveEditor to comfy_extras/nodes_curve.py with V3 schema
* feat: add HISTOGRAM type and histogram support to CurveEditor
* code improve
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Co-authored-by: Christian Byrne <cbyrne@comfy.org>
