Adds a new "basic" animation mode that uses React Flow's native animated
dashes — the entire stroke moves as dashes, with no solid line underneath.
Distinct from "snake" (moving dot) and "flow" (overlay on solid line).
- Frontend: new Basic button in EdgeModal, animMode mapping, passes
animated={true} to BaseEdge when mode is "basic"
- Backend: normalize_animated accepts "basic" as a valid value
- Tests: EdgeModal + canvas round-trip tests for basic mode
- Drag waypoints to reshape edges; double-click a waypoint to remove it
- + handles at segment midpoints to insert new waypoints
- Bezier style: catmull-rom smooth curves through waypoints
- Smooth style: rounded-corner polyline with soft 45° snap (snaps within 15px)
- First + handle biased to source axis for perpendicular node exit
- snap45both: ray-intersection solver ensures both adjacent segments snap to 45° simultaneously
- Clear path button in EdgeModal when waypoints exist
- Waypoints serialised/deserialised with canvas state
Pouzor