plot styles: the CTB/STB model and codec come from the codec crate

Cargo: codec d36331d, kernel 60f086b, graph 74aac56.

The table model and its file codec now live in `codec::plot_style`
(opencadcodec#53) and are re-exported here. What stays is where tables
come from: the plot styles folder, the session registry, the shipped
tables, and saving to disk, as the `PlotStyleTableExt` trait.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ocs_plugin_api/Cargo.toml

@@ -15,7 +15,7 @@ serde_json = { version = "1", optional = true }
 # Pulled in only by the `host` feature, which adds the `opencadcodec`-typed
 # `HostApi` runtime surface. The default crate stays dependency-free so engine
 # crates and external tooling can depend on the manifest/ribbon contract cheaply.
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "eaa6d79", optional = true, features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d36331d", optional = true, features = ["serde"] }
 
 # Runtime IPC and serialization (host feature only).
 interprocess = { version = "2", optional = true }
@@ -39,7 +39,7 @@ serde_json = "1"
 serde = { version = "1", features = ["derive"] }
 cargo-lock = "11"
 # opencadcodec is scanned at build time to generate the embedded type registry.
-codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "eaa6d79", features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "d36331d", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"