Feat: ROADMAP Phase 1-5 batch — trim/extend, plot scale, viewport UX, mline caps, table alignment

- TRIM/EXTEND: Ray and XLine entities supported as cutting boundaries and trim targets;
  trim results in Ray→Line/Ray, XLine→Ray/Ray or Line; hover preview added
- Plot scale override: Fit/1:1/1:2/1:5/1:10/1:20/1:50/1:100/2:1 buttons added to Page Setup
  panel; PageSetupCommit applies scale to PlotSettings
- Viewport UX: locked viewport gets orange border; selected viewport gets white border
- Named view → viewport assignment: Choice dropdown in properties panel copies
  view_target/direction/height to the viewport entity
- MLine caps: perpendicular start/end cap lines added for open (non-closed) MLines
- Wipeout polygon grips: boundary vertices become editable grips when clipping_enabled+Polygonal;
  world→pixel back-projection on drag
- Table cell alignment: CellStyle.alignment (1-9) drives left/center/right + top/middle/bottom
  text positioning; cxf::measure_text() helper added
- New commands/features: DIMCONTINUE (DCO), DIMBASELINE (DBA), TOLERANCE (TOL), TABLE,
  ATTDEF, ATTEDIT, ATTDISP, BREAKATPOINT (BAP), PLOTWINDOW (PW), MLINE (ML);
  DIMSTYLE/DIMCURRENT/CLAYER/LTSCALE/CELTSCALE/SCALETEXT/XDATA/UCSICON/REGEN/DRAWORDER extended
- PLINE arc mode: A/L/CLOSE text input, bulge computation, arc preview
- Warning cleanup: removed unused imports and unreachable patterns

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

src/app/properties.rs

@@ -82,6 +82,13 @@ impl H7CAD {
                             .map(|u| u.name.clone())
                             .unwrap_or_default();
 
+                        // Collect available named view names.
+                        let view_names: Vec<String> = self.tabs[i].scene.document.views
+                            .iter()
+                            .map(|v| v.name.clone())
+                            .filter(|n| !n.is_empty())
+                            .collect();
+
                         if let Some(geom) = sections.last_mut() {
                             geom.props.push(crate::scene::object::Property {
                                 label: "Frozen Layers".to_string(),
@@ -100,6 +107,16 @@ impl H7CAD {
                                     },
                                 });
                             }
+                            if !view_names.is_empty() {
+                                geom.props.push(crate::scene::object::Property {
+                                    label: "Named View".to_string(),
+                                    field: "vp_named_view",
+                                    value: crate::scene::object::PropValue::Choice {
+                                        selected: String::new(),
+                                        options: view_names,
+                                    },
+                                });
+                            }
                         }
                     }