Pin bread-utils to bread-ecosystem v0.7.2. breadshot listen
subscribes to bread.command.shot.**, runs the same region capture
as the CLI (clipboard-only), and emits bread.shot.region.done /
.failed.
Emit bread.shot.captured after a successful grim/wl-copy capture.
Fail-silent when breadd is down. No command verbs — breadshot is a
one-shot CLI; Lua workflows should bread.exec("breadshot …").