Extend canvas ROI editing beyond move:
- Box: drag corners/edges to resize (handles shown on the selected ROI).
- Circle: drag the perimeter to resize, interior to move.
- Azimuthal: drag the inner/outer arc to change the Q/d range, or a radial
edge to rotate a phi bound; sampled through the geometry so it tracks
the conic.
- Delete removes the selected ROI (the view now takes keyboard focus).
All edits go through the same live, throttled SetROIDefinition path.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>