Filesystem helpers shared by manifest loading and the providers that read staged artifacts from disk.

read/1 returns the raw File.posix() reason on failure rather than a formatted string, so a caller can tell :enoent -- a licensed artifact the operator has not dropped into the cache yet, which has a specific remedy -- from :eacces or another failure it cannot recover from the same way. format_error/2 turns that reason into the message most callers want to surface, once they have decided they have nothing more specific to say.

read/1 looks like it adds nothing over calling File.read/1 directly -- it is a one-line body with no branching -- but the raw passthrough is the point, not an oversight: GeoGenius.Manifest needs the unformatted reason to build its own ManifestError, carrying path and a formatted reason as separate fields, while GeoGenius.Providers.GeoJSON formats the same reason into a plain string. Pre-formatting inside read/1 would serve the second caller and break the first. This module's actual job is owning format_error/2 -- the one formatting rule every caller shares -- while leaving each caller free to decide whether and how to wrap the raw reason. test/geo_genius/files_test.exs pins the raw-passthrough contract down with an assertion in its own name.