Migrated from 4-position handle system (top/right/bottom/left) to React Flow's
easy-connect pattern where the entire node surface is connectable and edges
dynamically route to the nearest point on the node border.
Key changes:
- Migration utility removes old 4-position handle references for backwards compatibility
- Full-coverage invisible handles on CustomNode and GroupNode (maximized state)
- Floating edges use node.measured dimensions and node.internals.positionAbsolute
- useInternalNode hook for correct absolute positioning of nodes in groups
- All edges now omit handle fields, allowing dynamic border calculations
This improves UX by making nodes easier to connect (whole surface vs tiny handles)
and edges intelligently route to optimal connection points.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
