just --dump should provide recipe order

I was hoping to write something that ran the recipes in a justfile in order (lots of individual set up steps to bootstrap a new machine). I can use `just --summary --unsorted`, but it would be cleaner to use `just --dump --dump-format=json` and sort by some recipe order info.

Start by locating the handling for `just --dump` and `--dump-format=json`, then inspect how recipe order is represented internally. Define what order information the JSON output should expose so recipes can be sorted, and verify the result against a justfile containing multiple setup recipes.

Written by the indexing model from the issue text.