feat: Introduce EnhancedGridMap addon for advanced grid management and procedural generation, and StaticTektonManager for tekton spawning and placement.

addons/enhanced_gridmap/enhanced_gridmap.gd

@@ -16,6 +16,7 @@ signal grid_updated
 @export var hover_item: int = 1
 @export var start_item: int = 2
 @export var end_item: int = 3
+@export var immutable_items: Array[int] = [4] # Items that cannot be randomized/reset
 
 var current_mesh_library: MeshLibrary
 var grid_data: Array = [] # 3D array [floor][row][column]
@@ -270,6 +271,11 @@ func randomize_floor(floor_index: int, custom_rng_callable: Callable = Callable(
 	
 	for x in range(columns):
 		for z in range(rows):
+			# Check if current item on this floor is immutable
+			var current_item_on_floor = get_cell_item(Vector3i(x, floor_index, z))
+			if current_item_on_floor in immutable_items:
+				continue
+
 			# IMPORTANT: Only place items if Floor 0 has a walkable tile
 			var floor_0_item = get_cell_item(Vector3i(x, 0, z))
 			var is_ground = (floor_0_item == normal_items[0]) # Assuming 0 is ground