add audio_manager and code refactoring

core/ai/agents/base/ai_base.gd

@@ -0,0 +1,48 @@
+extends CharacterBody3D
+
+class_name AIBase
+
+@export var speed: float = 4.0
+@export var enable_state_machine: bool = true: 
+	set(value):
+		enable_state_machine = value
+		toggle_enable_state_machine()
+
+
+@onready var patrol_radius_shape: CollisionShape3D = $%PatrolRadiusShape
+@onready var nav_agent: NavigationAgent3D = $%NavigationAgent3D
+@onready var state_machine: StateMachine = $%StateMachine
+
+
+func _ready() -> void:
+	randomize()
+	toggle_enable_state_machine()
+
+func toggle_enable_state_machine() -> void:
+	state_machine.enable = enable_state_machine
+
+func _physics_process(delta: float) -> void:
+	if !enable_state_machine:
+		return
+
+	state_machine.physics_process(delta)
+
+	if nav_agent.is_navigation_finished():
+		velocity = Vector3.ZERO
+		move_and_slide()
+		return
+
+	var next_point = nav_agent.get_next_path_position()
+	var direction = global_position.direction_to(next_point)
+	
+	velocity.x = direction.x * speed
+	velocity.z = direction.z * speed
+	
+	move_and_slide()
+
+func navigate_to_random_point() -> void:
+	var nav_map_rid = get_world_3d().get_navigation_map()
+	var patrol_radius = patrol_radius_shape.shape.radius
+	var target_point_in_space = global_position + Vector3(randf_range(-1, 1), 0, randf_range(-1, 1)).normalized() * randf_range(0, patrol_radius)
+	var closest_valid_point = NavigationServer3D.map_get_closest_point(nav_map_rid, target_point_in_space)
+	nav_agent.target_position = closest_valid_point