feat(select): Previous / Last keywords at Select objects prompts

Standard selection keywords, available typed or as prompt buttons in
every gathering command (#426): P / PREVIOUS re-selects the set the
last finishing command worked on (now captured before the working set
is dropped), and L / LAST selects the most recently created object of
the current space (highest handle among its selectable wires). Handled
centrally in the step router, so the command line, the option buttons
and the automation feeder share one implementation; deleted objects
and locked layers are filtered out.

Co-Authored-By: Claude Fable 5 <[email protected]>

src/modules/draw/select.rs

@@ -11,7 +11,7 @@
 use acadrust::Handle;
 use glam::DVec3;
 
-use crate::command::{CadCommand, CmdResult};
+use crate::command::{CadCommand, CmdOption, CmdResult};
 use crate::scene::model::wire_model::WireModel;
 
 pub struct SelectObjectsCommand {
@@ -68,6 +68,18 @@ impl CadCommand for SelectObjectsCommand {
         true
     }
 
+    // Clickable selection keywords (#426): Previous re-selects the set the
+    // last command worked on, Last the most recently created object. The
+    // keywords are consumed centrally in `try_selection_keyword`, so they
+    // also work typed — these buttons just surface them.
+    fn options(&self) -> Vec<CmdOption> {
+        if self.commit_on_enter {
+            vec![CmdOption::new("Previous", "P"), CmdOption::new("Last", "L")]
+        } else {
+            Vec::new()
+        }
+    }
+
     fn on_selection_complete(&mut self, handles: Vec<Handle>) -> CmdResult {
         if self.commit_on_enter {
             // Keep gathering: remember the running set and update the prompt.