fix(commands): deny list during BEDIT

Refuse LAYOUT, VPORTS, MVIEW, WBLOCK, PURGE, RENAME, REFEDIT,
REFEDIT_BEGIN and PLOT from the command line while a block editor
session is open, matching the reference product's
"<CMD> command not allowed in block editor" behaviour (spec section 8,
based on the V7 hands-on check). XREF, NEW, OPEN and SAVEAS stay
allowed. The service-level RENAME guard stays as defense in depth.

src/app/command_driver/tests.rs

@@ -1318,6 +1318,115 @@ mod bedit_characterization_tests {
         assert!(app.tabs[tab].block_edits.is_empty());
     }
 
+    /// V7 (reference check): while a block editor session is open this
+    /// command set is refused outright with "not allowed in block editor";
+    /// the refusal pushes no undo entry and starts no command.
+    #[test]
+    fn locked_deny_list_refuses_while_session_open() {
+        let mut app = OpenCADStudio::new_for_test();
+        let (insert, _) = setup_block_and_insert(&mut app);
+        let tab = app.active_tab;
+        let _ = app.dispatch_command(&format!("BEDIT_BEGIN:{}", insert.value()));
+        assert!(
+            app.tabs[tab].active_block_edit.is_some(),
+            "setup: BEDIT_BEGIN should open a session"
+        );
+        let undo_depth = app.tabs[tab].history.undo_stack.len();
+        for verb in [
+            "LAYOUT",
+            "VPORTS",
+            "MVIEW",
+            "WBLOCK",
+            "PURGE",
+            "RENAME",
+            "REFEDIT",
+            "REFEDIT_BEGIN",
+            "PLOT",
+        ] {
+            let revision = app.command_line.error_revision;
+            let _ = app.dispatch_command(verb);
+            assert_eq!(
+                app.command_line.error_revision,
+                revision.wrapping_add(1),
+                "{verb} must refuse with a command-line error"
+            );
+            assert!(
+                app.command_line
+                    .last_error
+                    .as_deref()
+                    .unwrap_or_default()
+                    .contains("command not allowed in block editor"),
+                "{verb}: got {:?}",
+                app.command_line.last_error
+            );
+            assert!(
+                app.tabs[tab].active_block_edit.is_some(),
+                "{verb} must keep the session open"
+            );
+            assert!(
+                app.tabs[tab].active_cmd.is_none(),
+                "{verb} must not install a command"
+            );
+            assert_eq!(
+                app.tabs[tab].history.undo_stack.len(),
+                undo_depth,
+                "{verb} must push no undo entry"
+            );
+        }
+    }
+
+    /// Spec 8: a rejected command must not cancel a running command — the
+    /// deny hook sits before the running-command teardown.
+    #[test]
+    fn locked_deny_list_does_not_cancel_a_running_command() {
+        let mut app = OpenCADStudio::new_for_test();
+        let (insert, _) = setup_block_and_insert(&mut app);
+        let tab = app.active_tab;
+        let _ = app.dispatch_command(&format!("BEDIT_BEGIN:{}", insert.value()));
+        assert!(app.tabs[tab].active_block_edit.is_some());
+        let _ = app.dispatch_command("LINE");
+        assert_eq!(
+            app.tabs[tab].active_cmd.as_deref().map(|cmd| cmd.name()),
+            Some("LINE"),
+            "setup: LINE should be running inside the session"
+        );
+        let _ = app.dispatch_command("LAYOUT");
+        assert!(app
+            .command_line
+            .last_error
+            .as_deref()
+            .unwrap_or_default()
+            .contains("command not allowed in block editor"));
+        assert_eq!(
+            app.tabs[tab].active_cmd.as_deref().map(|cmd| cmd.name()),
+            Some("LINE"),
+            "the refused command must leave the running LINE untouched"
+        );
+    }
+
+    /// V7: the reference keeps XREF, NEW, OPEN, SAVEAS and BEDIT available
+    /// inside the editor — the deny list must not touch them.
+    #[test]
+    fn locked_deny_list_leaves_v7_allowed_commands_alone() {
+        for verb in ["XREF", "NEW", "OPEN", "SAVEAS", "BEDIT"] {
+            let mut app = OpenCADStudio::new_for_test();
+            let (insert, _) = setup_block_and_insert(&mut app);
+            let tab = app.active_tab;
+            let _ = app.dispatch_command(&format!("BEDIT_BEGIN:{}", insert.value()));
+            assert!(app.tabs[tab].active_block_edit.is_some());
+            let _ = app.dispatch_command(verb);
+            assert!(
+                !app.command_line
+                    .last_error
+                    .as_deref()
+                    .unwrap_or_default()
+                    .contains("not allowed in block editor"),
+                "{verb} is available in the reference session and must not be denied: {:?}",
+                app.command_line.last_error
+            );
+        }
+    }
+
     // ---- documenting: today's behavior, expected to flip in Phase 1 ----
 
     /// Discard removes local before-images before drawing undo resumes.