fix(xclip): follow-ups to the XCLIP merge

- An inverted clip's roundtrip record goes in the filter's extension
  dictionary through the codec's own API (ensure_extension_dictionary /
  xrecord / extension_dictionary_handle) instead of a scan of every
  object, which the renderer ran for each clipped reference.
- Pin cadcodec 1c3be0c (the DXF writer now links a spatial filter's
  extension dictionary, so that record is not left unreferenced) and
  cadkernel deb529b; plugin crates and the Python plugin lock follow.
- The XCLIP boundary preview stays f64.

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 `acadrust`-typed
 # `HostApi` runtime surface. The default crate stays dependency-free so engine
 # crates and external tooling can depend on the manifest/ribbon contract cheaply.
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "d290dbe", optional = true, features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "1c3be0c", 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"
 # acadrust is scanned at build time to generate the embedded type registry.
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "d290dbe", features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "1c3be0c", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"