Big feature day - built out a proper level editor. The LevelEditor component provides buttons for export, import, creating new levels, and saving/loading player positions. I also added a placement mode system so you can click on the grid to place different cell types like walls and goals.

Added a bunch of tutorial levels to help new players learn the mechanics, plus a new “ladders” level. The editor now supports placing red goals and the whole Edit tab in the level menu is functional. This was done on a separate branch and merged back to main once it was working.