- Add constraint validation during drag using ItineraryConstraints
- Calculate invalid zones and barrier games when drag starts
- Apply visual dimming (alpha 0.3) to invalid drop zones during drag
- Highlight barrier games with gold border when dragging travel segments
- Block invalid drops using ItineraryConstraints.isValidPosition validation
- Add haptic feedback for drag interactions:
- Medium impact on pickup
- Light impact when entering valid zone
- Warning notification when entering invalid zone
- Soft impact on drop
The drag state is tracked via draggingItem, invalidRowIndices, and
barrierGameIds properties. Visual feedback is applied and removed
via applyDragVisualFeedback/removeDragVisualFeedback methods.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>