bd: point the Dolt remote at dolt.srht.bigb.es and enable auto-push

bd init wrote the git URL into sync.remote, which Dolt cannot push to. Point
it at the companion database instead and turn on auto-push (30s debounce, 60s
timeout) so a bead created in a session does not sit only in the local store.

bd: update sync.remote

bd: clear sync.remote

bd init: initialize beads issue tracking