The storage primitives a StateStore-colocated leadership seat exposes (design §5.1's default Leadership implementation — one row, one statement). Fief.Leadership.FromStore is the notify-loop adapter campaigning through these; any store module implementing them (Fief.Authority.Local today, the Postgres adapter at M7 — its fief_leader UPDATE is exactly try_lead/3) plugs in unchanged. This keeps the adapter generic without coupling it to Fief.Authority.Local: the adapter depends on this two-callback behaviour, never on a concrete store.

Semantics:

• try_lead/3 — one campaign step. Grants a fresh monotonic term if the seat is empty or expired; renews (same term) if node_id already holds it; {:error, {:held, holder, term}} otherwise. Terms are per-namespace and never reissued lower — that monotonicity is what makes StateStore term validation a fence against zombie planners.
• leader/1 — the current holder, per Fief.Leadership.leader/1 semantics, judged on the arbiter's clock.

Leadership needs none of the lease layer's clock conservatism (design §5.1): it gates only epoch/term-fenced writes, so no margins, no self-fencing — expiry here costs a leaderless interval, never safety.