- ue_import_site.py: switch walkable surfaces (terrain, road, sidewalks) from
CTF_USE_COMPLEX_AS_SIMPLE to CTF_USE_SIMPLE_AND_COMPLEX so the capsule
blocks against the auto-generated simple collision as well as triangles.
- Re-imported site meshes, rebuilt DemoMap with the PlayerStart cap at Z300.
Unresolved: packaged plain launch still falls through at spawn in the last
verified run (capsule Z-123 -> -1960, no ground trace hit). User confirms the
site geometry RENDERS (visible in the distance) but the player is not standing
on it. Needs an in-editor/in-window collision verification — headless traces
are unreliable. Continue on this branch; do not merge to main.