feat: P.3.1 reference test-module — lib-core.maps assertions

assets/tiles/demo_tilemap.tilemap.json

@@ -0,0 +1,8 @@
+{
+  "id": "demo_tilemap",
+  "tile_size": 32,
+  "tiles": [
+    {"id": "grass", "walkable": true,  "color": [110, 170, 80]},
+    {"id": "stone", "walkable": false, "color": [120, 120, 120]}
+  ]
+}