Adds initial test stage

Adds a basic test stage scene with a root node, a grid, and a tilemap layer.
This provides a foundation for creating test levels and environments.

stages/test/Test.tscn

@@ -0,0 +1,10 @@
+[gd_scene load_steps=2 format=3 uid="uid://yfs1g77wwlvv"]
+
+[ext_resource type="Script" uid="uid://ddyl4y27q03qo" path="res://stages/test/test.gd" id="1_xne4r"]
+
+[node name="Test" type="Node2D"]
+script = ExtResource("1_xne4r")
+
+[node name="TestGrid" type="Node2D" parent="."]
+
+[node name="TestLayer" type="TileMapLayer" parent="TestGrid"]

stages/test/test.gd

@@ -0,0 +1 @@
+extends Node2D

stages/test/test.gd.uid

@@ -0,0 +1 @@
+uid://ddyl4y27q03qo