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_stab_test.gd

@@ -45,7 +45,7 @@ func _run() -> void:
 	root.add_child(bull)
 	bull.global_position = Vector3(0.0, 0.0, standoff + 3.0)
 
-	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)             # _ready acquires the bull from the "player" group
 	mat.global_position = Vector3.ZERO
 	mat.set_physics_process(false)  # we drive the attack tick ourselves, isolated from the AI