Rebuilds a session from its journal — the crash-recovery path. Outcomes, the running net, and
the chain head all re-derive from the journal rows; a rebuilt session can keep recording (if
it never settled) or go straight to settle, and settle keying each chunk on its posting's
existence makes a half-settled session finish rather than double-post. Recovery probes for a
prior settlement posting: a session that already settled refuses further movements the same
way a live one does, so recovery can finish a settle but never reopen a settled epoch.
Rebuilds a session from its journal — the crash-recovery path. Outcomes, the running net, and the chain head all re-derive from the journal rows; a rebuilt session can keep recording (if it never settled) or go straight to settle, and settle keying each chunk on its posting's existence makes a half-settled session finish rather than double-post. Recovery probes for a prior settlement posting: a session that already settled refuses further movements the same way a live one does, so recovery can finish a settle but never reopen a settled epoch.