`_board_dispatched` is an in-memory, never-expiring set of
(agent_slug, task_id). The solo exploration dispatchers consulted it, so an
exploration whose propose verb rejected was never retried for the life of the
process — Periscope, Sentinel, Scales and Barfly each spawned once on
2026-07-25, failed, and sat PENDING until the stack restarted.
The guard was written for the two-reviewer board REVIEW pass, where it is
correct: a reviewer has no verb to advance the task, so a respawn can only
loop. An explorer is the opposite — `propose_*` is exactly such a verb, so a
respawn can and should advance it.
Drop it from the 15 `_dispatch_*_exploration` functions. Bounding falls to
`_pm_respawn_should_gate`, which is what actually bounds a loop: DB-persisted,
reset by a status change, and cooled down so a deploy that fixes the cause
lets the work resume. `_dispatch_board_reviewer` keeps the set (its
`_board_review_complete` reads it as a has-run signal) as does vault
curation (same-process race guard behind its own durable marker).
The 14 `*_dispatch_is_one_shot` tests asserted the old contract on the false
rationale that board roles have no progression verb; they now assert a second
tick re-attempts.
Co-authored-by: Renn F <rennf93@users.noreply.github.com>
