feat: Introduce PlayerMovementManager to manage player movement, rotation, attack mode push mechanics, and grid-based collision detection.

addons/enhanced_gridmap/enhanced_gridmap.gd

@@ -555,6 +555,13 @@ func find_path(start: Vector2, end: Vector2, floor_index: int = 0, clear_path_vi
 	
 	var start_point = start.y * columns + start.x
 	var end_point = end.y * columns + end.x
+	
+	if not is_position_valid(Vector2i(int(start.x), int(start.y))) or not is_position_valid(Vector2i(int(end.x), int(end.y))):
+		return []
+		
+	if not astar.has_point(start_point) or not astar.has_point(end_point):
+		return []
+		
 	path = astar.get_point_path(start_point, end_point)
 	
 	if visualize: