MineInstance reads a Mine and draws it (latest sim body at the grid height, spin, real-time pulse by arming and
trigger); ZoneRenderer makes one per Zone.Mines add and plays the blast on remove; EntityInstance gives a mine
layer no effect manager. AetherDb mine-launcher authors the item; the catalog, prefab and scene wiring follow in
later commits, so this one does not build a playable mine (no MinePrefab yet).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
