The watch daemon publishes bread.crumbs.profile.changed and
bread.crumbs.health.changed on real transitions (not every poll tick)
and honors bread.command.crumbs.set_profile via the existing
state::set_profile path. BreadClient is fail-silent: if breadd is
down, breadcrumbs behaves exactly as before.
Document the contract in EVENTS.md. CLAUDE.md now points at
CONTRIBUTING (single-trunk, no three-branch model), bakery, and
EVENTS.md.
