refactor(*): Restructure game into reusable Arena/GameMode architecture with controller-driven ships, adding Free Play and Match modes

Game/scripts/ship_controller.gd

@@ -0,0 +1,12 @@
+class_name ShipController
+extends Node
+
+# Base class for anything that drives a Ship: local player input, an AI
+# policy, or network replication. The ship pulls exactly one action per
+# physics tick, so controllers stay deterministic and ordering-free.
+# The base implementation returns a zero action — a ship with a base
+# controller (or none) is inert but still physically simulated.
+
+
+func get_action() -> ShipAction:
+	return ShipAction.new()