PDFSHXTEXT: recognise SHX text geometry as MText

Adds PDFSHXTEXT with the PDF Text Recognition Settings dialog, its
command-line form, the PDFSHXLAYER / PDFSHXBESTFONT / PDFSHXTEXTSETTINGS
variables and the profile settings they are kept in.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/update/file.rs

@@ -825,6 +825,7 @@ impl OpenCADStudio {
             ucs_ortho: crate::modules::view::view_cmd::ucs_ortho(),
             ucs_view: crate::modules::view::view_cmd::ucs_view(),
             layout_create_viewport: crate::scene::layout_create_viewport(),
+            pdf_shx_text: crate::modules::insert::pdf_shx_text::settings(),
             ncopy_bind: self.ncopy_bind,
             cursor_type: self.cursor_type,
             crosshair_color: self.crosshair_color,
@@ -969,6 +970,7 @@ impl OpenCADStudio {
         crate::modules::view::view_cmd::set_ucs_ortho(s.ucs_ortho);
         crate::modules::view::view_cmd::set_ucs_view(s.ucs_view);
         crate::scene::set_layout_create_viewport(s.layout_create_viewport);
+        crate::modules::insert::pdf_shx_text::set_settings(s.pdf_shx_text.clone());
         self.ncopy_bind = s.ncopy_bind;
         self.cursor_type = s.cursor_type;
         self.crosshair_color = s.crosshair_color;

src/app/update/mod.rs

@@ -2409,6 +2409,7 @@ impl OpenCADStudio {
             Message::AttdefDialog(message) => self.on_attdef_dialog(message),
             Message::FieldDialog(message) => self.on_field_dialog(message),
             Message::RefEditDialog(message) => self.update_refedit_dialog(message),
+            Message::PdfShxDialog(message) => self.update_pdf_shx_dialog(message),
             Message::PcManager(message) => self.update_pc_manager(message),
             Message::Count(message) => self.on_count(message),
             Message::SheetSet(message) => self.on_sheet_set(message),
@@ -9587,6 +9588,14 @@ impl OpenCADStudio {
                 if self.active_modal == Some(super::ModalKind::RefEdit) {
                     self.refedit_dialog = None;
                 }
+                // Cancel returns to PDFSHXTEXT's selection prompt.
+                if self.active_modal == Some(super::ModalKind::PdfShxSettings) {
+                    self.pdf_shx_dialog = None;
+                    self.close_active_modal();
+                    let i = self.active_tab;
+                    self.start_pdf_shx_gather(i);
+                    return self.focus_cmd_input();
+                }
                 // Cancelling the section settings drops the waiting extraction.
                 if self.active_modal == Some(super::ModalKind::PcSection) {
                     crate::modules::insert::pc_extract::drop_job();