MockJitoEngine — a deterministic stand-in for the Jito Block Engine, covering
the surface the SDK's MEV router needs: tip accounts, tip-floor percentiles,
bundle submission, and in-flight status polling. Landing is poll-driven and
configurable so tests can force the "bundle never lands -> fall back to RPC"
path that the bounty's automatic-fallback requirement demands.
MockJitoEngine — a deterministic stand-in for the Jito Block Engine, covering the surface the SDK's MEV router needs: tip accounts, tip-floor percentiles, bundle submission, and in-flight status polling. Landing is poll-driven and configurable so tests can force the "bundle never lands -> fall back to RPC" path that the bounty's automatic-fallback requirement demands.