Complete Region: create from a profile, plus tuple and int friendliness

RegionFromProfile reuses the REGION command's kernel calls; doc.solids.region
exposes it with layer and delete_source options. The lifecycle test builds
regions from real circle and polyline entities and covers refusals, a move,
both formats and undo. create_entity now accepts coordinate tuples for point
properties and every generated float setter accepts Python ints.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/ocs_plugin_api/src/host.rs

@@ -85,6 +85,11 @@ pub enum SolidOperation {
     /// Apply a rigid transform, given as a column-major 4x4 matrix, to an
     /// existing solid. Scaling and shear are refused.
     Transform { handle: Handle, matrix: [f64; 16] },
+    /// Build a planar region from one closed planar profile entity (a circle,
+    /// ellipse, closed polyline or spline, ...). The new region goes on
+    /// `layer`, or on the source's layer when `None`; `delete_source` erases
+    /// the profile afterwards, as the REGION command does.
+    RegionFromProfile { source: Handle, layer: Option<String>, delete_source: bool },
 }
 
 /// Value of a host-managed drafting or document setting exposed to plugins.

crates/ocs_plugin_api/src/ipc/v4/protocol.rs

@@ -114,6 +114,7 @@ mod tests {
                 layer: Some("SOLIDS".into()),
             },
             SolidOperation::Transform { handle: acadrust::Handle::new(7), matrix: [1.0; 16] },
+            SolidOperation::RegionFromProfile { source: acadrust::Handle::new(3), layer: None, delete_source: true },
         ] {
             let bytes = bincode::serialize(&PluginRequest::SolidOperation { operation: operation.clone() }).unwrap();
             assert!(matches!(bincode::deserialize::<PluginRequest>(&bytes).unwrap(),