Editor action `toggle-diff-gutter`.
Run it from the command palette or a key binding via the action id `toggle_diff_gutter`.
It is dispatched by `App::run_action("toggle_diff_gutter")` and, for editing actions, backed
by `Editor::toggle_diff_gutter` in `editor_core`. See `crates/vix-editor-core/spec/index.md` for the full
catalog.