- Add BoxShape3D to PrototypeTerminal (layer 1, walkable) so the player
cannot pass through; matches terminal mesh size.
- Bake navigation from collision layer 1 only so the player (layer 2) is
not merged into the mesh; reparent Player under NavigationRegion3D so
NavigationAgent3D resolves a valid map.
- Restore nav waypoint following for long horizontal legs; keep horizontal
steering toward next/goal so bump departure behavior stays sane.