- Add drape.rs for terrain hillshade landcover draping
- Add overlay.rs for route polylines, markers, and position puck
- Add icons.rs and icons/ directory for map icon management
- Update geometry.rs with 3D road elevation and join improvements
- Update tile.rs with unified road mesh rendering
- Update view.rs with seamless 2D/3D mode transitions
- Update style.rs with night themes and emissive roads
- Add i_overlay dependency for polygon boolean operations
- Update maps feature to include i_overlay
Key improvements:
- 3D road elevation and seam continuity
- Building shadow geometry and terrain cast shadows
- Route assistant and navigation layer support
- Clickable themes and night mode
- Water, grass, and shrub rendering
- Optimized road geometry and mode transitions
