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/modules/draw/modify/offset.rs

@@ -12,16 +12,16 @@
 
 use crate::entities::curve::{entity_curve, lwpolyline_world_xy};
 use crate::modules::draw::modify::spline_ops::spline_sample_xy;
-use acadrust::entities::LwVertex;
-use acadrust::entities::{
+use codec::entities::LwVertex;
+use codec::entities::{
     Arc as ArcEnt, Circle as CircleEnt, Ellipse as EllipseEnt, Line as LineEnt, LwPolyline,
     Spline as SplineEnt, XLine as XLineEnt,
 };
-use acadrust::{EntityType, Handle};
+use codec::{EntityType, Handle};
 // Polyline offsetting, and the angle normalisation that goes with it, come
 // from the kernel; only the entity conversion stays here.
-use cadkernel::geom2d::nurbs::clamped_uniform_knots;
-use cadkernel::geom2d::{
+use kernel::geom2d::nurbs::clamped_uniform_knots;
+use kernel::geom2d::{
     offset_polyline, Polyline as KernelPolyline, PolylineVertex as KernelVertex,
 };
 use glam::{DVec3, Vec3};
@@ -269,7 +269,7 @@ fn offset_spline(spl: &SplineEnt, dist: f64, side_pt: Vec3) -> Option<EntityType
     })?;
 
     // Offset each sample point along the local normal.
-    let offset_pts: Vec<acadrust::types::Vector3> = pts
+    let offset_pts: Vec<codec::types::Vector3> = pts
         .iter()
         .enumerate()
         .map(|(i, p)| {
@@ -290,14 +290,14 @@ fn offset_spline(spl: &SplineEnt, dist: f64, side_pt: Vec3) -> Option<EntityType
             let nx = -dy / len; // left perpendicular
             let ny = dx / len;
             let z = spl.control_points.first().map(|v| v.z).unwrap_or(0.0);
-            acadrust::types::Vector3::new(p[0] + sign * nx * dist, p[1] + sign * ny * dist, z)
+            codec::types::Vector3::new(p[0] + sign * nx * dist, p[1] + sign * ny * dist, z)
         })
         .collect();
 
     let _ = ts_knot;
     // Build a new spline from the offset control points (treat sample pts as fit pts → ctrl pts).
     let degree = spl.degree.max(1) as usize;
-    let new_ctrl: Vec<acadrust::types::Vector3> = offset_pts;
+    let new_ctrl: Vec<codec::types::Vector3> = offset_pts;
     let n_ctrl = new_ctrl.len();
     let mut new_spl = spl.clone();
     new_spl.common.handle = Handle::NULL;
@@ -364,7 +364,7 @@ fn perp_distance(entity: &EntityType, pt: Vec3) -> f64 {
 // ── Wire preview points ─────────────────────────────────────────────────────
 
 /// Preview density, matching the figure the drawn wires use.
-const PREVIEW_SEGMENTS_PER_RADIAN: f64 = cadkernel::geom2d::DEFAULT_SEGMENTS_PER_RADIAN;
+const PREVIEW_SEGMENTS_PER_RADIAN: f64 = kernel::geom2d::DEFAULT_SEGMENTS_PER_RADIAN;
 
 /// Preview points for an entity, from its own curve.
 ///
@@ -989,7 +989,7 @@ inventory::submit!(crate::command::CommandRegistration { names: &["OFFSET"] });
 #[cfg(test)]
 mod offset_tests {
     use super::*;
-    use acadrust::types::Vector2;
+    use codec::types::Vector2;
 
     fn rect(corners: &[[f64; 2]]) -> LwPolyline {
         LwPolyline {
@@ -1049,7 +1049,7 @@ mod option_tests {
     use super::*;
 
     fn line(x1: f64, y1: f64, x2: f64, y2: f64, handle: u64) -> EntityType {
-        let mut line = acadrust::entities::Line::from_coords(x1, y1, 0.0, x2, y2, 0.0);
+        let mut line = codec::entities::Line::from_coords(x1, y1, 0.0, x2, y2, 0.0);
         line.common.handle = Handle::new(handle);
         EntityType::Line(line)
     }