Modified src/topology/topology.jl to reflect new architecture:
- Clarify topology defines geometric shape only, not node count
- Document that node count comes from basis functions
- Add examples showing same topology with different bases (Quad4/8/9)
- Update docstring to reference new topology types (Segment, Triangle, etc.)
- Emphasize corner nodes only in topology API
- Remove references to old node-count-baked types (Tri3, Quad4, etc.)
Jukka Aho
07f1c690d2