CURVE node (#12757)

* 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

---------

Co-authored-by: Christian Byrne <cbyrne@comfy.org>

comfy_api/input/__init__.py

@@ -5,6 +5,10 @@ from comfy_api.latest._input import (
     MaskInput,
     LatentInput,
     VideoInput,
+    CurvePoint,
+    CurveInput,
+    MonotoneCubicCurve,
+    LinearCurve,
 )
 
 __all__ = [
@@ -13,4 +17,8 @@ __all__ = [
     "MaskInput",
     "LatentInput",
     "VideoInput",
+    "CurvePoint",
+    "CurveInput",
+    "MonotoneCubicCurve",
+    "LinearCurve",
 ]