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 <[email protected]>

src/scene/preview.rs

@@ -164,7 +164,7 @@ impl Scene {
             boundary_exterior: None,
             boundary_sources: None,
             boundary_paths: None,
-            style: acadrust::entities::HatchStyleType::Normal,
+            style: codec::entities::HatchStyleType::Normal,
             pattern: HatchPattern::Solid,
             name: "AREA_PREVIEW".into(),
             color: [0.0; 4],
@@ -224,11 +224,11 @@ impl Scene {
                 backdrop.pattern =
                     crate::scene::model::hatch_model::HatchPattern::Solid;
                 let (background_color, background_aci) = match background {
-                    acadrust::types::Color::ByLayer => {
+                    codec::types::Color::ByLayer => {
                         let layer = self.document.layers.get(&hatch.common.layer);
                         let aci = layer
                             .and_then(|layer| match &layer.color {
-                                acadrust::types::Color::Index(index) => Some(*index),
+                                codec::types::Color::Index(index) => Some(*index),
                                 _ => None,
                             })
                             .unwrap_or(0);
@@ -241,10 +241,10 @@ impl Scene {
                             aci,
                         )
                     }
-                    acadrust::types::Color::ByBlock => (style.0, style.4),
-                    acadrust::types::Color::Index(index) => (
+                    codec::types::Color::ByBlock => (style.0, style.4),
+                    codec::types::Color::Index(index) => (
                         crate::scene::convert::tess_util::aci_to_rgba(
-                            &acadrust::types::Color::Index(index),
+                            &codec::types::Color::Index(index),
                         ),
                         index,
                     ),
@@ -284,7 +284,7 @@ impl Scene {
         self.selection.borrow_mut().preview_box = None;
     }
 
-    pub fn wire_models_for(&self, handles: &[acadrust::Handle]) -> Vec<WireModel> {
+    pub fn wire_models_for(&self, handles: &[codec::Handle]) -> Vec<WireModel> {
         handles
             .iter()
             .flat_map(|h| {
@@ -307,7 +307,7 @@ impl Scene {
     /// Current candidate geometry for a hot grip. Solid-history candidates
     /// live outside the document until placement; ordinary entities continue
     /// to use their current tessellation.
-    pub fn grip_wire_models_for(&self, handles: &[acadrust::Handle]) -> Vec<WireModel> {
+    pub fn grip_wire_models_for(&self, handles: &[codec::Handle]) -> Vec<WireModel> {
         handles
             .iter()
             .flat_map(|handle| {
@@ -425,7 +425,7 @@ impl Scene {
 
     /// Build wire models for an arbitrary slice of entities (e.g. clipboard contents).
     /// Entities need not be in the document — they are tessellated directly.
-    pub fn wires_for_entities(&self, entities: &[acadrust::EntityType]) -> Vec<WireModel> {
+    pub fn wires_for_entities(&self, entities: &[codec::EntityType]) -> Vec<WireModel> {
         entities
             .iter()
             .flat_map(|e| self.tessellate_one(e))
@@ -442,7 +442,7 @@ impl Scene {
     /// (insertion base at origin) for the block-palette thumbnail. Nested INSERTs
     /// expand through the block cache. Unknown / empty block → `vec![]`.
     pub(crate) fn block_preview_wires(&self, name: &str) -> Vec<WireModel> {
-        use acadrust::EntityType;
+        use codec::EntityType;
         let Some(br) = self.document.block_records.get(name) else {
             return vec![];
         };
@@ -463,9 +463,9 @@ impl Scene {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use acadrust::entities::Line;
-    use acadrust::types::Vector3;
-    use acadrust::EntityType;
+    use codec::entities::Line;
+    use codec::types::Vector3;
+    use codec::EntityType;
 
     #[test]
     fn block_preview_wires_tessellates_block_entities() {