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/snap.rs

@@ -8,8 +8,8 @@ use glam::{DVec3, Mat4, Vec3};
 use iced::time::Instant;
 use iced::{Point, Rectangle};
 
-use cadkernel::geom2d::Curve;
-use acadrust::types::Handle;
+use kernel::geom2d::Curve;
+use codec::types::Handle;
 
 use crate::command::{DimensionAssociationSource, TangentObject};
 use crate::scene::model::wire_model::{SnapHint, TangentGeom, WireModel};
@@ -2868,7 +2868,7 @@ fn tangent_line_endpoints(
 }
 
 fn curves_in_frame(wire: &WireModel, frame: &WirePlane, tol: f64) -> Option<Vec<Curve>> {
-    use cadkernel::geom2d::{Arc as KArc, Circle as KCircle, Ellipse as KEllipse, EllipseArc as KEllipseArc, Line as KLine};
+    use kernel::geom2d::{Arc as KArc, Circle as KCircle, Ellipse as KEllipse, EllipseArc as KEllipseArc, Line as KLine};
 
     let mut curves = Vec::new();
 
@@ -2986,11 +2986,11 @@ pub(crate) fn exact_curve_intersections(
         return None;
     }
 
-    let tolerance = cadkernel::geom2d::Tolerance::new(1e-9_f64.max(PLANE_TOL));
+    let tolerance = kernel::geom2d::Tolerance::new(1e-9_f64.max(PLANE_TOL));
     let mut points: Vec<DVec3> = Vec::new();
     for ca in &curves_a {
         for cb in &curves_b {
-            let crossings = cadkernel::geom2d::intersect(ca, cb, tolerance);
+            let crossings = kernel::geom2d::intersect(ca, cb, tolerance);
             for c in crossings {
                 let pt = frame.to_3d(c.point);
                 if !points.iter().any(|existing| existing.distance_squared(pt) <= 1e-12) {
@@ -3081,11 +3081,11 @@ fn seg_intersect_2d(a0: Point, a1: Point, b0: Point, b1: Point) -> Option<(f32,
 
 /// Returns the two external tangent points on an XY circle.
 fn circle_tangent_points(p: Vec3, center: Vec3, radius: f32) -> Option<(Vec3, Vec3)> {
-    let curve = cadkernel::geom2d::Curve::Circle(cadkernel::geom2d::Circle {
+    let curve = kernel::geom2d::Curve::Circle(kernel::geom2d::Circle {
         centre: [center.x as f64, center.y as f64],
         radius: radius as f64,
     });
-    let points = cadkernel::geom2d::tangent_from(&curve, [p.x as f64, p.y as f64]);
+    let points = kernel::geom2d::tangent_from(&curve, [p.x as f64, p.y as f64]);
     let [first, second] = points.as_slice() else {
         return None;
     };
@@ -3102,15 +3102,15 @@ fn planar_circle_tangent_points(
     axis_y: [f64; 3],
     radius: f64,
 ) -> Vec<DVec3> {
-    let plane = cadkernel::space::Plane::from_axes(center, axis_x, axis_y);
+    let plane = kernel::space::Plane::from_axes(center, axis_x, axis_y);
     let Some(from) = plane.project(from.to_array()) else {
         return Vec::new();
     };
-    let curve = cadkernel::geom2d::Curve::Circle(cadkernel::geom2d::Circle {
+    let curve = kernel::geom2d::Curve::Circle(kernel::geom2d::Circle {
         centre: [0.0, 0.0],
         radius,
     });
-    cadkernel::geom2d::tangent_from(&curve, from)
+    kernel::geom2d::tangent_from(&curve, from)
         .into_iter()
         .map(|point| DVec3::from_array(plane.point_at(point.point)))
         .collect()
@@ -3125,17 +3125,17 @@ fn arc_tangent_points(
     start_angle: f64,
     end_angle: f64,
 ) -> Vec<DVec3> {
-    let plane = cadkernel::space::Plane::from_axes(center, axis_x, axis_y);
+    let plane = kernel::space::Plane::from_axes(center, axis_x, axis_y);
     let Some(from) = plane.project(from.to_array()) else {
         return Vec::new();
     };
-    let curve = cadkernel::geom2d::Curve::Arc(cadkernel::geom2d::Arc {
+    let curve = kernel::geom2d::Curve::Arc(kernel::geom2d::Arc {
         centre: [0.0, 0.0],
         radius,
         start_angle,
         end_angle,
     });
-    cadkernel::geom2d::tangent_from(&curve, from)
+    kernel::geom2d::tangent_from(&curve, from)
         .into_iter()
         .map(|point| DVec3::from_array(plane.point_at(point.point)))
         .collect()