asteria-game: stub the cluster-reconvergence finally-check
Adds testnets/asteria_game/no-op-finally.sh and bind-mounts it over the sidecar:f889dbc image's /opt/antithesis/test/v1/convergence/finally_tips_agree.sh. That driver enforces "all producer tips at exact same slot at end-of-run" via an SDK Always assertion. On 1h runs under fault injection the tips drift recovers slowly after faults stop and the check fires false purely on duration, not on a real reconvergence bug. The check is also orthogonal to the asteria game contract this testnet scores — asteria observes the chain through relay1 and tolerates short-lived tip lag. Other convergence drivers (eventually_converged, parallel_driver_tip_agreement, serial_driver_tip_agreement) are unaffected and continue to run from the unmodified sidecar image. Their during-fault and probabilistic checks remain a real cluster-health signal.