Reorganize into role-based folders and consolidate art

Move every script and scene into role-based directories (actors/, systems/, ui/,
levels/, props/) and all raw art under art/ (grouped by role, snake_case,
Extract-Textures GLBs), dropping Blender version-suffix noise. Filenames are
snake_case (PascalCase reserved for class_name) to avoid case-insensitive
filesystem aliasing on the web/macOS targets. Routes the bull's hits through the
typed DamageEvent pipeline and wires the bull's abilities to the Fx library.
Updates CLAUDE.md's folder-layout overview to match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CCyaJPTHCH9EDthpf4A5Sj

tests/matador_taunt_react_test.gd

@@ -38,7 +38,7 @@ func _make_bull() -> CharacterBody3D:
 
 
 func _make_taunting_matador(_bull: CharacterBody3D) -> CharacterBody3D:
-	var mat := (load("res://Matador.tscn") as PackedScene).instantiate() as CharacterBody3D
+	var mat := (load("res://actors/matador/matador.tscn") as PackedScene).instantiate() as CharacterBody3D
 	root.add_child(mat)
 	mat.global_position = Vector3.ZERO
 	mat.set_physics_process(false)     # we drive _tick_wander ourselves, no brain