feat(plugin): AutoCAD-compatible PAUSE, ENTER keyword, and command streaming

crates/ocs_plugin_api/src/ipc/protocol.rs

@@ -142,6 +142,8 @@ pub enum PluginRequest {
     AddLayer(crate::host::LayerConfig),
     /// Modify specified properties of an existing layer in the active document.
     ModifyLayer(crate::host::LayerConfig),
+    /// Run a command on the active document tab's command line (AutoLISP style).
+    ExecuteCommand(String),
 }
 
 /// Responses the host sends back for `PluginRequest`.