PCEXTRACTSECTION: Extract Section Lines dialog

Picking the cloud opens the Extract Section Lines from Point Cloud
dialog with the reference's settings and defaults: entire cross section
or perimeter only, maximum points to process (slider and field, with
the estimated time), output layer (Use Current or a layer), colour,
lines or 2D polylines with their width, minimum line length and connect
lines tolerance (each measurable by two points on screen), collinear
angle tolerance (0-10) and Preview result. Create extracts; with the
preview it asks [Accept/Settings/Undo] and Settings reopens the dialog.
The settings are kept for the session. Automation action pc_section.

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

src/app/view/modal.rs

@@ -31,6 +31,7 @@ impl OpenCADStudio {
             },
             Some(K::PointCloudAttach) => crate::t!("Attach Point Cloud").into_owned(),
             Some(K::PointCloudColorMap) => crate::t!("Point Cloud Color Map").into_owned(),
+            Some(K::PcSection) => crate::t!("Extract Section Lines from Point Cloud").into_owned(),
             Some(K::UnderlayLayers) => crate::t!("Underlay Layers").into_owned(),
             Some(K::PdfImportSettings) => crate::t!("PDF Import Settings").into_owned(),
             Some(K::PdfImportFile) => crate::t!("Import PDF").into_owned(),
@@ -536,6 +537,10 @@ impl OpenCADStudio {
                     crate::ui::window::pdf_dialogs::view_point_cloud_color_map(state, flow)
                 })
             }
+            super::super::ModalKind::PcSection => {
+                let state = self.pc_section.as_ref()?;
+                sized_flow(ex, 760, 470, |flow| crate::ui::window::pdf_dialogs::view_pc_section(state, flow))
+            }
             super::super::ModalKind::UnderlayLayers => {
                 let state = self.underlay_layers.as_ref()?;
                 sized_flow(ex, 460, 520, |flow| {