`~/.config/rtx/settings.toml`

[jdx]

the global config's [settings] section should be broken out into its own file: ~/.config/rtx/settings.toml. This way it's clear that settings only go in this location and can't be in just any .rtx.toml file. This also cleans up the codebase since settings logic (which needs to be fast and read every time the CLI runs) can be separate from config loading (slow, only needs to be done sometimes).

Of course we should keep the ability to have [settings] in the global config for backwards compatibility if settings.toml doesn't exist.