Count: measured messages and listing, groups, Current area, boundary checks, fills and solids recoloured

- COUNTCOLOR / COUNTERRORCOLOR / COUNTSERVICE reject any other value with
  the range message; COUNTTABLE ? lists in the reference order, padded,
  22 lines a page with Press ENTER to continue:, then the totals.
- Target picks report N found / N found, M total; several objects (or one
  that is not a block reference) count their copies, shown as Geometries
  in the palette.
- Current area is the area in use (kept aside by Entire model space),
  otherwise all of model space; an invalid Object boundary ends with the
  reference message.
- Count colours reach solids and fills; the palette list and the count
  are recomputed only when the drawing changes.

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

src/app/update/file.rs

@@ -5544,7 +5544,7 @@ impl OpenCADStudio {
     /// Current visible rectangle in the active space. The result is deliberately
     /// not clamped to the paper sheet: Display and Window may include the grey
     /// canvas outside the sheet, matching Model-space plotting.
-    pub(in crate::app) fn display_plot_window(&self) -> Option<(f64, f64, f64, f64)> {
+    fn display_plot_window(&self) -> Option<(f64, f64, f64, f64)> {
         let scene = &self.tabs[self.active_tab].scene;
         let (canvas_w, canvas_h) = scene.selection.borrow().vp_size;
         let viewport = if scene.current_layout == "Model" {