game: add weapon active ability

scenes/weapons/weapon_base.gd

@@ -7,6 +7,7 @@ extends Node2D
 @export var attack_duration: float
 @export var attack_range: float
 
+@onready var active_cd_timer: Timer = $ActiveCDTimer
 
 func _on_attack_cd_timer_timeout() -> void:
 	do_attack()
@@ -15,6 +16,15 @@ func _on_attack_cd_timer_timeout() -> void:
 func do_attack() -> void:
 	push_error("%s does not implement do_attack" % self)
 
+func do_active() -> void:
+	if not active_cd_timer.is_stopped():
+		return
+	active_cd_timer.start()
+	_do_active()
+	
+
+func _do_active() -> void:
+	push_error("%s does not implement do_active" % self)
 
 func find_target_in_radius() -> EnemyBase:
 	var space_state: PhysicsDirectSpaceState2D = get_world_2d().direct_space_state