I hope the way I worded this question is not as confused as I feel right now!
There are several ways you could handle the edge of the tile. One suggestion I would make is go into one of the box stores where they have kitchen displays. Notice the different ways they finish the edge of countertops where they have tiled the countertops.
Lowe's I know offers a oak trim piece in the flooring section that is designed for finishing off counter tops but could easily finish of the edge of your landing as well.
You could also go down in the stair parts section of these stores and get a piece of 3/4 inch oak nosing and butt you tile up to it. With the thickness of the hardibacker or concrete board, thinset and tile you will be close to the same thickness of the 3/4 inch nosing.
Very often in the ceramic tile section of the store they have bullnose tile that are can also work. Also consider the tiles designed for chair railings as these can work well too.