wakeups

LISTEN/NOTIFY push wake-ups, fed by the V002 schema triggers on every write that makes a job claimable. Delivery is at COMMIT, so a wake-up never precedes the row it announces; batch inserts collapse to one notification.

While collected, this flow holds ONE dedicated connection from the DataSource (LISTEN is connection-scoped) and occupies one PostgresStoreConfig.dispatcher thread. The connection must reach Postgres directly or through a session-mode pooler; PgBouncer transaction pooling breaks LISTEN.

One hint is emitted immediately after LISTEN is established, so work enqueued while no listener existed (startup, a reconnect gap) is claimed at once instead of at the next poll. A dead connection makes the flow throw: reconnecting is the caller's loop (the runtime restarts collection with backoff, and its poll ticker covers the gap), so the worst failure mode of push is poll latency.