feat(python): linetypes and layouts (doc.linetypes, doc.layouts)

TableOperation gains simple-linetype create/modify/rename/delete (standard names
taken, rename follows layers and entities, guarded delete) and paper-space
layout create/rename/delete/set-current/set-page (default page setup and sheet
viewport, the application's own layout switch, Model protected). CTAB now reports
the current layout. Real-IPC audit with DWG/DXF persistence and undo, IPC and
Python unit tests, docs.

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

crates/ocs_plugin_api/src/host.rs

@@ -147,6 +147,34 @@ pub enum TableOperation {
     /// new entity's handle. Edit and delete members with the ordinary entity
     /// operations.
     BlockEntityAdd { block: String, entity: EntityType },
+    /// Create a simple linetype. `pattern` is signed lengths in drawing units:
+    /// positive is a dash, negative a gap, zero a dot (2-12 elements with at
+    /// least one dash or dot and one gap). Returns the linetype's handle.
+    LinetypeCreate { name: String, description: String, pattern: Vec<f64> },
+    /// Change a simple linetype's description or pattern in place.
+    LinetypeModify { name: String, description: Option<String>, pattern: Option<Vec<f64>> },
+    /// Rename a linetype; layers and entities that use it follow.
+    LinetypeRename { from: String, to: String },
+    /// Delete a linetype that no layer, entity, dimension style or the current
+    /// setting uses. `Continuous`, `ByLayer` and `ByBlock` are never deleted.
+    LinetypeDelete { name: String },
+    /// Create a paper-space layout with the default page setup and sheet viewport.
+    LayoutCreate { name: String },
+    /// Rename a paper-space layout (never `Model`).
+    LayoutRename { from: String, to: String },
+    /// Delete a paper-space layout and everything on it (never `Model`).
+    LayoutDelete { name: String },
+    /// Switch the active layout (`Model` or a paper-space layout).
+    LayoutSetCurrent { name: String },
+    /// Change a paper-space layout's sheet: size in millimetres, rotation in
+    /// degrees (0, 90, 180 or 270) and a custom plot scale (numerator,
+    /// denominator).
+    LayoutSetPage {
+        name: String,
+        paper_size: Option<[f64; 2]>,
+        rotation: Option<u16>,
+        scale: Option<[f64; 2]>,
+    },
 }
 
 /// The style tables `TableOperation` can rename, delete or make current.

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

@@ -145,6 +145,15 @@ mod tests {
                 block: "C".into(),
                 entity: acadrust::EntityType::Line(acadrust::entities::Line::new()),
             },
+            TableOperation::LinetypeCreate { name: "L".into(), description: "d".into(), pattern: vec![1.0, -1.0] },
+            TableOperation::LinetypeModify { name: "L".into(), description: None, pattern: Some(vec![2.0, -2.0]) },
+            TableOperation::LinetypeRename { from: "L".into(), to: "M".into() },
+            TableOperation::LinetypeDelete { name: "M".into() },
+            TableOperation::LayoutCreate { name: "S".into() },
+            TableOperation::LayoutRename { from: "S".into(), to: "T".into() },
+            TableOperation::LayoutDelete { name: "T".into() },
+            TableOperation::LayoutSetCurrent { name: "Model".into() },
+            TableOperation::LayoutSetPage { name: "S".into(), paper_size: Some([420.0, 297.0]), rotation: Some(90), scale: Some([1.0, 50.0]) },
         ] {
             let bytes = bincode::serialize(&PluginRequest::TableOperation { operation: operation.clone() }).unwrap();
             assert!(matches!(bincode::deserialize::<PluginRequest>(&bytes).unwrap(),