feat:(recuration): added planet list singelton

Core/Singeltons/planets_singelton.gd

@@ -0,0 +1,11 @@
+extends Node
+
+var planets: Array[Node] = []
+
+
+func register(planet: Node) -> void:
+	planets.append(planet)
+
+
+func unregister(planet) -> void:
+	planets.erase(planet)

Core/Singeltons/planets_singelton.gd.uid

@@ -0,0 +1 @@
+uid://dhdnbucgojrv6