feat: node graph overlay; move to opencadcodec/opencadkernel/opencadgraph

The codec and kernel repositories and crates are renamed opencadcodec and
opencadkernel. Inside OCS they are depended on under short keys, so code
reads `codec::`, `kernel::` and the new `graph::` (opencadgraph, the node
graph engine). File-format and protocol spellings stay as they were: the
ACIS product id `acadrust`, the ACADRUST_* switches and the plugin
version keys `acadrust_version` / `acadrust_source`.

A button left of MCP on the command line opens a translucent node graph
over the viewport, with a palette of object, input, math, logic, list,
text and geometry nodes added by click or drag. An object node owns
drawing entities and its rows are the Properties panel's own rows for
them: the single-object page is extracted from refresh_properties as
entity_property_sections, values use the control protocol's
property_json, and writes go through set_property_value with a property
target override, so the panel, MCP and the graph share one read/write
path. A list reaching an object row makes one entity per element. Each
graph action is one undo step; the canvas pans and zooms.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/scene/dimension_assoc_chain.rs

@@ -4,11 +4,11 @@
 //! transformed through their block instances. The caller projects viewport
 //! references onto the sheet. All arithmetic uses `f64`.
 
-use acadrust::objects::AssocDimensionReference;
-use acadrust::types::{Handle, Matrix4, Transform, Vector3};
-use acadrust::{CadDocument, EntityType};
-use cadkernel::geom2d::{closest_point, Curve as KernelCurve};
-use cadkernel::space::Plane;
+use codec::objects::AssocDimensionReference;
+use codec::types::{Handle, Matrix4, Transform, Vector3};
+use codec::{CadDocument, EntityType};
+use kernel::geom2d::{closest_point, Curve as KernelCurve};
+use kernel::space::Plane;
 
 use crate::entities::curve::entity_curve;
 
@@ -319,14 +319,14 @@ fn quadrant_point(
     };
     let valid_angle = |angle: f64| match &planar.curve {
         KernelCurve::Arc(arc) => {
-            cadkernel::geom2d::angle_within_arc(angle, arc.start_angle, arc.end_angle)
+            kernel::geom2d::angle_within_arc(angle, arc.start_angle, arc.end_angle)
         }
         _ => true,
     };
     let at_angle = |angle: f64| {
         lift(
             &planar.plane,
-            KernelCurve::Circle(cadkernel::geom2d::Circle { centre, radius })
+            KernelCurve::Circle(kernel::geom2d::Circle { centre, radius })
                 .point_at(angle.rem_euclid(std::f64::consts::TAU) / std::f64::consts::TAU),
         )
     };
@@ -359,7 +359,7 @@ fn node_point(entity: &EntityType) -> Option<Vector3> {
 fn perpendicular_point(entity: &EntityType, from: Vector3) -> Option<Vector3> {
     let planar = entity_curve(entity)?;
     let uv = planar.plane.project(dpoint(from))?;
-    cadkernel::geom2d::snap::perpendicular_from(&planar.curve, uv)
+    kernel::geom2d::snap::perpendicular_from(&planar.curve, uv)
         .into_iter()
         .map(|candidate| lift(&planar.plane, candidate.point))
         .min_by(|a, b| distance_squared(*a, from).total_cmp(&distance_squared(*b, from)))
@@ -384,13 +384,13 @@ pub(crate) fn perpendicular_in_model(
     let normal = x.cross(y).try_normalize()?;
     let axis_y = normal.cross(axis_x);
     let plane = Plane::from_axes(dpoint(origin), axis_x.to_array(), axis_y.to_array());
-    let curve = source.curve.transformed(&cadkernel::geom2d::Transform {
+    let curve = source.curve.transformed(&kernel::geom2d::Transform {
         origin: [0.0, 0.0].into(),
         x_axis: [x.dot(axis_x), x.dot(axis_y)].into(),
         y_axis: [y.dot(axis_x), y.dot(axis_y)].into(),
     })?;
     let uv = plane.project(dpoint(from))?;
-    cadkernel::geom2d::snap::perpendicular_from(&curve, uv)
+    kernel::geom2d::snap::perpendicular_from(&curve, uv)
         .into_iter()
         .map(|candidate| lift(&plane, candidate.point))
         .min_by(|a, b| distance_squared(*a, from).total_cmp(&distance_squared(*b, from)))
@@ -436,7 +436,7 @@ fn tangent_point(
     let planar = entity_curve(entity)?;
     let from = context.from?;
     let uv = planar.plane.project(dpoint(from))?;
-    cadkernel::geom2d::snap::tangent_from(&planar.curve, uv)
+    kernel::geom2d::snap::tangent_from(&planar.curve, uv)
         .into_iter()
         .map(|candidate| lift(&planar.plane, candidate.point))
         .min_by(|a, b| {
@@ -446,7 +446,7 @@ fn tangent_point(
 }
 
 fn spline_tangent_point(
-    spline: &acadrust::entities::Spline,
+    spline: &codec::entities::Spline,
     reference: &AssocDimensionReference,
     context: FeatureContext,
 ) -> Option<Vector3> {
@@ -497,16 +497,16 @@ fn intersection_point(
     let origin = glam::DVec2::from_array(map([0.0, 0.0])?);
     let x = glam::DVec2::from_array(map([1.0, 0.0])?) - origin;
     let y = glam::DVec2::from_array(map([0.0, 1.0])?) - origin;
-    let second = second.curve.transformed(&cadkernel::geom2d::Transform {
+    let second = second.curve.transformed(&kernel::geom2d::Transform {
         origin: origin.to_array().into(),
         x_axis: x.to_array().into(),
         y_axis: y.to_array().into(),
     })?;
     let hint_uv = first.plane.project(dpoint(hint))?;
-    let mut points: Vec<_> = cadkernel::geom2d::intersect(
+    let mut points: Vec<_> = kernel::geom2d::intersect(
         &first.curve,
         &second,
-        cadkernel::geom2d::Tolerance::new(1e-9),
+        kernel::geom2d::Tolerance::new(1e-9),
     )
     .into_iter()
     .map(|hit| hit.point)
@@ -515,17 +515,17 @@ fn intersection_point(
         // Extended apparent intersections are meaningful for straight lines.
         // Curved geometry must actually cross after projection.
         if let (KernelCurve::Line(a), KernelCurve::Line(b)) = (&first.curve, &second) {
-            let extend = |line: &cadkernel::geom2d::Line| {
-                KernelCurve::XLine(cadkernel::geom2d::XLine {
+            let extend = |line: &kernel::geom2d::Line| {
+                KernelCurve::XLine(kernel::geom2d::XLine {
                     base: line.start,
                     direction: [line.end[0] - line.start[0], line.end[1] - line.start[1]],
                 })
             };
             points.extend(
-                cadkernel::geom2d::intersect(
+                kernel::geom2d::intersect(
                     &extend(a),
                     &extend(b),
-                    cadkernel::geom2d::Tolerance::new(1e-9),
+                    kernel::geom2d::Tolerance::new(1e-9),
                 )
                 .into_iter()
                 .map(|hit| hit.point),