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/entities/match_props.rs

@@ -8,8 +8,8 @@
 /// strings, block names) or placement (positions, rotations of the object
 /// itself). Text formatting crosses TEXT ↔ MTEXT; the dimension style crosses
 /// Dimension / Leader / Tolerance.
-pub fn match_special_props(src: &acadrust::EntityType, dst: &mut acadrust::EntityType) {
-    use acadrust::EntityType as E;
+pub fn match_special_props(src: &codec::EntityType, dst: &mut codec::EntityType) {
+    use codec::EntityType as E;
 
     // Text-ish source formatting.
     let text_fmt = match src {
@@ -290,8 +290,8 @@ pub struct PolylineMatchStyle {
 }
 
 impl PolylineMatchStyle {
-    pub fn from_entity(entity: &acadrust::EntityType) -> Option<Self> {
-        use acadrust::EntityType as E;
+    pub fn from_entity(entity: &codec::EntityType) -> Option<Self> {
+        use codec::EntityType as E;
 
         match entity {
             E::LwPolyline(poly) => {
@@ -329,7 +329,7 @@ impl PolylineMatchStyle {
                 };
                 Some(Self {
                     plinegen: poly.flags.bits()
-                        & acadrust::entities::PolylineFlags::LINETYPE_CONTINUOUS.bits()
+                        & codec::entities::PolylineFlags::LINETYPE_CONTINUOUS.bits()
                         != 0,
                     widths,
                 })
@@ -338,8 +338,8 @@ impl PolylineMatchStyle {
         }
     }
 
-    pub fn apply_to(&self, entity: &mut acadrust::EntityType) {
-        use acadrust::EntityType as E;
+    pub fn apply_to(&self, entity: &mut codec::EntityType) {
+        use codec::EntityType as E;
 
         match entity {
             E::LwPolyline(poly) => {
@@ -360,13 +360,13 @@ impl PolylineMatchStyle {
             }
             E::Polyline2D(poly) => {
                 let mut bits = poly.flags.bits();
-                let flag = acadrust::entities::PolylineFlags::LINETYPE_CONTINUOUS.bits();
+                let flag = codec::entities::PolylineFlags::LINETYPE_CONTINUOUS.bits();
                 if self.plinegen {
                     bits |= flag;
                 } else {
                     bits &= !flag;
                 }
-                poly.flags = acadrust::entities::PolylineFlags::from_bits(bits);
+                poly.flags = codec::entities::PolylineFlags::from_bits(bits);
                 let sampled = resample_widths(&self.widths, poly.vertices.len());
                 let first = sampled.first().copied().unwrap_or((0.0, 0.0));
                 let can_use_defaults = widths_are_same(&sampled);
@@ -440,9 +440,9 @@ pub enum MatchLayerError {
 /// that resolve to nothing are skipped. Lock-filtering, undo, dirty-state and
 /// command-line echo stay caller-side in `handle_match_entity_layer`.
 pub fn match_layer_kernel(
-    doc: &mut acadrust::CadDocument,
-    dest: &[acadrust::Handle],
-    src: acadrust::Handle,
+    doc: &mut codec::CadDocument,
+    dest: &[codec::Handle],
+    src: codec::Handle,
 ) -> Result<usize, MatchLayerError> {
     let layer = doc
         .get_entity(src)
@@ -508,8 +508,8 @@ impl Default for MatchOpts {
 /// stay caller-side; lock-filtering, undo, dirty-state, selection and echo
 /// stay caller-side too.
 pub fn match_properties_kernel(
-    src: &acadrust::EntityType,
-    dst: &mut acadrust::EntityType,
+    src: &codec::EntityType,
+    dst: &mut codec::EntityType,
     opts: &MatchOpts,
 ) {
     if opts.copy_common {
@@ -553,19 +553,19 @@ pub fn match_properties_kernel(
 mod match_layer_kernel_tests {
     use super::{MatchLayerError, match_layer_kernel};
 
-    fn line_on(layer: &str) -> acadrust::EntityType {
-        let mut line = acadrust::entities::Line::new();
+    fn line_on(layer: &str) -> codec::EntityType {
+        let mut line = codec::entities::Line::new();
         line.common.layer = layer.to_string();
-        acadrust::EntityType::Line(line)
+        codec::EntityType::Line(line)
     }
 
-    fn layer_of(doc: &acadrust::CadDocument, handle: acadrust::Handle) -> String {
+    fn layer_of(doc: &codec::CadDocument, handle: codec::Handle) -> String {
         doc.get_entity(handle).unwrap().common().layer.clone()
     }
 
     #[test]
     fn copies_src_layer_onto_every_dest_and_returns_count() {
-        let mut doc = acadrust::CadDocument::new();
+        let mut doc = codec::CadDocument::new();
         let src = doc.add_entity(line_on("WALLS")).unwrap();
         let a = doc.add_entity(line_on("0")).unwrap();
         let b = doc.add_entity(line_on("0")).unwrap();
@@ -580,7 +580,7 @@ mod match_layer_kernel_tests {
 
     #[test]
     fn missing_src_errors_and_leaves_dest_untouched() {
-        let mut doc = acadrust::CadDocument::new();
+        let mut doc = codec::CadDocument::new();
         let dest = doc.add_entity(line_on("0")).unwrap();
         let missing = doc.allocate_handle();
 
@@ -592,7 +592,7 @@ mod match_layer_kernel_tests {
 
     #[test]
     fn skips_missing_dest_handles_but_counts_the_rest() {
-        let mut doc = acadrust::CadDocument::new();
+        let mut doc = codec::CadDocument::new();
         let src = doc.add_entity(line_on("WALLS")).unwrap();
         let dest = doc.add_entity(line_on("0")).unwrap();
         let missing = doc.allocate_handle();
@@ -607,10 +607,10 @@ mod match_layer_kernel_tests {
 #[cfg(test)]
 mod match_properties_kernel_tests {
     use super::{MatchOpts, match_properties_kernel};
-    use acadrust::EntityType;
+    use codec::EntityType;
 
     fn line_src() -> EntityType {
-        let mut line = acadrust::entities::Line::new();
+        let mut line = codec::entities::Line::new();
         line.common.layer = "WALLS".to_string();
         line.common.linetype_scale = 2.5;
         line.thickness = 1.25;
@@ -618,7 +618,7 @@ mod match_properties_kernel_tests {
     }
 
     fn line_dst() -> EntityType {
-        let mut line = acadrust::entities::Line::new();
+        let mut line = codec::entities::Line::new();
         line.common.layer = "0".to_string();
         line.common.linetype_scale = 1.0;
         line.thickness = 0.0;
@@ -643,12 +643,12 @@ mod match_properties_kernel_tests {
 
     #[test]
     fn transfers_text_style_via_special_props_flag() {
-        let mut src_text = acadrust::entities::Text::new();
+        let mut src_text = codec::entities::Text::new();
         src_text.value = "SRC".into();
         src_text.style = "BIG".into();
         src_text.height = 5.0;
         let src = EntityType::Text(src_text);
-        let mut dst_text = acadrust::entities::Text::new();
+        let mut dst_text = codec::entities::Text::new();
         dst_text.value = "DST".into();
         let mut dst = EntityType::Text(dst_text);