forked from 1b-agent/opencadstudio-upstream
The Current Vertex row is now a ◀ / ▶ stepper (new PropValue::Stepper) showing "i / N". Stepping it moves the panel's focus through the polyline's vertices — Vertex X/Y and the per-vertex start/end widths show and edit the focused vertex instead of always the first — and the focused vertex's grip is drawn hot (filled) in the drawing so it's visible while navigating. Focus wraps around and resets to the first vertex when the selection changes. Adds Area and Length to the LwPolyline Geometry group (Polyline2D already had them). Applies to LwPolyline and Polyline2D. The focused vertex is threaded to the per-entity property builder/editor through a dispatch thread-local (like the curve-tolerance override), so the PropertyEditable trait signatures are unchanged. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>