Reports drift between the site's theme overlays and the installed theme.
Usage
mix cherry.theme.diff [TEMPLATE] [--source DIR] [--apply] [--json]Statuses: current (upstream unchanged), auto_updatable (upstream
moved, your copy untouched — --apply re-ejects it with fresh
provenance), conflict (both moved; resolve by hand or re-eject with
theme.eject --force), untracked (no provenance header). This is
the managed-drift answer to silently frozen theme copies.