_release_failed_bet and _release_failed_withdrawal restored the balance, freed
the reserved UTXOs and (for a bet) removed the participant without calling
broadcaster.publish(), so every dashboard kept showing the phantom bet and the
reduced balance until its next poll — while the success path and the
reconciler's own abandon path both published.
The two regression tests pre-open the round before subscribing: place_bet opens
one itself, and that publish() would otherwise satisfy the assertion whether or
not the rollback published anything.