fix(layout): place a window-plot sheet around its plot window

A layout plotted by window drew its sheet at the paper-space origin, so
the title block sat on the grey background away from the paper. The
sheet now centres on the plot window, or sits at the plot offset from it
when the plot is not centred.

Bump codec 8aa574a (polyline vertices in owned-handle order, which fixes
self-crossing viewport clip boundaries), kernel d79bb30, graph 4810ee0.

Fixes #1678

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 = "bc350f2", optional = true, features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8aa574a", 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 = "bc350f2", features = ["serde"] }
+codec = { package = "opencadcodec", git = "https://github.com/HakanSeven12/opencadcodec.git", rev = "8aa574a", features = ["serde"] }
 
 [dev-dependencies]
 serde_json = "1"