Changed
- Improved the Label dialog so blank labels cannot be submitted and shared fields can be edited across Shapes with different Labels when validate_label is exact (#2587)
- Reworded the LineStrip tooltip to "Click to place linestrip points; Ctrl+click places the last one"; label, shortcut, icon, and behavior are unchanged (#2595)
- Polygon, linestrip, and AI-Points clicks share one canvas handler; Ctrl+Shift+click now also places the last linestrip point, matching AI-Points (#2596)