Selection: count duplicates and removals from the step's own picks

The count line now uses the objects the selection step itself picked
(a click, a window or crossing, a lasso, a fence, Last / Previous /
All): "N found (D duplicate), M total" when some were chosen already,
"N found, R removed, M total" in remove mode, "N found, M total" when a
removal picks objects that were not chosen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/app/mod.rs

@@ -799,6 +799,9 @@ pub(super) struct OpenCADStudio {
     /// The selection the gathering command had after the last pick (keyed by
     /// the command), for the `N found, M total` line.
     pub(crate) selection_report: Option<(usize, Vec<codec::Handle>)>,
+    /// The objects the last selection step picked (a click, a window, a
+    /// fence, Last / Previous / All) and whether it removed them.
+    pub(crate) last_pick: Option<(Vec<codec::Handle>, bool)>,
     /// The Edit Reference dialog's remembered settings.
     pub(crate) refedit_options: crate::app::settings::RefEditOptions,
     /// BLOCKREDEFINEMODE (0–2).
@@ -4686,6 +4689,7 @@ impl OpenCADStudio {
             block_freq: std::collections::HashMap::new(),
             block_mru_list: 50,
             selection_report: None,
+            last_pick: None,
             refedit_options: Default::default(),
             block_redefine_mode: 1,
             block_navigate: ".".to_string(),