M1d: creatures, hunting, weapons, food buffs and the hide cloak

- Rabbits, deer and boars with procedural meshes and animated legs, a
  state machine (idle/wander/flee/charge/dead) and heightmap steering that
  avoids water, cliffs, the world edge, trees and buildings
- Spawner keeps a habitat-based budget around the player (6/4/3)
- Melee needs a weapon or tool (club, spear, axe, pickaxe); box sweep hits
- Wooden spear (thrust or throw) and crude bow with draw-scaled arrows;
  projectiles stick in the world as saved pickups
- Carcasses: E to butcher for meat, hide and embedded arrows
- Boars charge and gore when hit; hurt flash and a brief healing pause
- Cooked meat gives Well fed (faster stamina and healing); buffs saved
- Hide cloak: wear for warmth, saved, goes in the grave on death
- Feathers as meadow pickups (appended, existing save ids unchanged)
- New test_creatures_combat suite; run_all.sh gets a per-suite time limit

scripts/player/player.gd

@@ -27,6 +27,8 @@ var selected := 0
 var ui_open := false                 ## set by the inventory screen; freezes look/move
 var hands: Node3D
 var survival: Node                   ## health / stamina / hunger / warmth (survival.gd)
+var worn := ""                       ## item id of the cloak you're wearing ("" = none)
+signal worn_changed
 
 var _gravity: float = ProjectSettings.get_setting("physics/3d/default_gravity", 9.8)