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]>

docs/cadkernel-body-path.md

@@ -1,4 +1,4 @@
-# Scripting ACIS bodies through cadkernel: findings and plan
+# Scripting ACIS bodies through opencadkernel: findings and plan
 
 Investigation of the blocker on **Solid3D, Body, Region and Surface**
 (`docs/plugin-host-model-coverage-ledger.md`). The blocker said a script can
@@ -7,7 +7,7 @@ forbids rewriting an opaque payload without a proven lossless path. This note
 records what OCS's own kernel path can already do, measured with two spike tests
 (`spike_kernel_body_round_trip`, `spike_kernel_timings` in
 `src/app/plugin_host.rs`, both `#[ignore]` because they are slow in a debug
-build). Measured on cadcodec `5b682ed` / cadkernel `6f046af`, debug build.
+build). Measured on opencadcodec `5b682ed` / opencadkernel `6f046af`, debug build.
 
 **Conclusion:** the blocker was overstated. OCS already owns a kernel-backed
 create/transform/boolean pipeline whose output is verified lossless before it is
@@ -63,7 +63,7 @@ Two things to understand about "lossless":
 
 ## Design
 
-The obstacle is the channel. The generic entity path moves an acadrust
+The obstacle is the channel. The generic entity path moves an opencadcodec
 `EntityType` from the plugin to the host; the plugin has no kernel and must never
 see or rewrite ACIS bytes. Three ways to give a script the operations:
 
@@ -141,11 +141,11 @@ Phase 1 alone would move Solid3D from blocked to complete-in-OCS.
 ## Boolean timings (release build)
 
 Measured 2026-09-20 in a scratch crate built with `--release` (opt-level 3)
-against the same cadkernel revision OCS pins (`6f046af`, features `acis` and
+against the same opencadkernel revision OCS pins (`6f046af`, features `acis` and
 `offset`), calling exactly what OCS's `solid_model::boolean_result` calls:
 `brep::operation_tolerance` then `brep::combine`. A debug build of OCS is about
 22 times slower, so booleans must never be exercised in a debug test run. The
-scratch program is not in the repository; to repeat it, depend on cadkernel at
+scratch program is not in the repository; to repeat it, depend on opencadkernel at
 that revision and time `brep::combine` on `brep::make::{cuboid, cylinder,
 sphere, torus}` operands.