v1.1.3

Features

• Polygon — minimal TAC, exact clip: redundant polygon vertices are now dropped from the TAC (and greyed) by a single geometric rule — a vertex is dropped iff the triangle it forms with its current neighbours doesn't overlap the FIR, so removing it provably can't move the clipped area. This unifies collinear vertices (flat triangle), runs dragged well outside the FIR (triangle outside it), and keeps every genuine FIR-boundary corner and interior vertex (their triangle dips into the FIR). Result: the fewest points needed to describe the cut, with the clipped area unchanged — no collapse, no over-simplification to a triangle. Replaces the previous distance-tolerance (Douglas-Peucker) collinear pass for polygons.

Fixes

• Polygon transform handle never hides a vertex: the polygon's scale/rotate handle now rests just outside the bounding box (like the line/corridor/buffer handles) instead of on the corner, so it can't end up on top of a vertex (which made that vertex impossible to grab). Dragging a vertex towards it simply grows the box and the handle keeps clear.
• Collinearity detected for any aligned vertex, not just the dragged one: the polygon's TAC-minimisation rule now drops a vertex when its triangle with its neighbours is near-flat (within 0.02·span), re-evaluating the whole ring every frame. So aligning a vertex by moving one of its neighbours (e.g. an endpoint) greys/drops the now-collinear middle vertex too — previously only the actively-dragged vertex was snapped. The drag-time snap capture was likewise widened to 0.02·span (more magnetic).