.arcconfig

lfs: factor out a method for extracting the pointer of a single file

This will be useful for filesets, among other things, instead of traversing the
whole context.

{
    "conduit_uri": "https://phab.mercurial-scm.org/api",
    "repository.callsign": "HG",
    "arc.land.onto.default": "@",
    "base": "hg:.^"
}