feat: plot a model-space window to PDF

Pick a rectangular window in model space with the existing PLOTWINDOW command (now enabled in model space, previously paper-space only) and export it to a PDF at a chosen ISO paper size (A4-A0), orientation and scale (fit or ratio). The window is a hard clip boundary. Adds paper-size presets, a window-to-sheet transform, scale + clip support in the PDF exporter, and Page Setup controls (format/orientation/pick window).

src/io/print_to_printer.rs

@@ -57,6 +57,8 @@ pub async fn print_wires(
         offset_x,
         offset_y,
         rotation_deg,
+        1.0,
+        None,
         &tmp_path,
         plot_style.as_ref(),
     )?;