chore(beads): enable Dolt auto-push to dolt.srht.bigb.es

Beads changes were only reaching the remote on a manual bd dolt push, so
issue state drifted from the tracker between sessions. bd has native
auto-push (debounced, pushes to the configured origin remote); it was
simply never enabled — sync.remote was set but dolt.auto-push was unset.

Enable it with an explicit 5m debounce rather than relying on the implicit
default. Verified end-to-end: a write fires "dolt auto-push: pushed
successfully", and a fresh dolt clone of the remote shows this session's
closed beads (spec-jjo, spec-mfm, spec-ejq.1) as closed.

Also commits the JSONL exports, which were stale from this session's work.

chore(beads): track the spec.sr.ht issue backlog

Seven issues under the epic: Phases 3-5 (write plane -> review UI ->
deferred pile, chained by blocks), the loose-ends bucket of latent bugs,
and two ops tasks (nav restart, stale apk pins). Exported to a
git-tracked JSONL so the backlog is durable and portable, not only in the
local embedded Dolt DB.