feat: add Dust 2 level builder and implement pause menu UI with settings and loadout management

debug/dust2_level_builder.gd

@@ -208,6 +208,11 @@ func _build_dust2_layout() -> void:
 	add_child(combat_area)
 
 func _build_dust2_dummies() -> void:
+	# Do not spawn dummies in real multiplayer matches
+	var nm = get_node_or_null("/root/NetworkManager")
+	if nm and nm.multiplayer.multiplayer_peer is ENetMultiplayerPeer:
+		return
+		
 	var spawn_dummy = func(pos: Vector3, rot_y: float):
 		var dummy = load("res://entities/killable_dummy.gd").new()
 		dummy.position = pos