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_web_worker/Cargo.toml

@@ -8,7 +8,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "d290dbe", features = ["serde"] }
+acadrust = { git = "https://github.com/HakanSeven12/cadcodec.git", rev = "1c3be0c", features = ["serde"] }
 bincode = "1.3"
 serde = { version = "1", features = ["derive"] }
 console_error_panic_hook = "0.1"