Central Dogma: Hard-coded ZooKeeper replication secret 'ch4n63m3' with silent fallback enables cluster takeover

Vulnerability ZooKeeperReplicationConfig.secret silently substitutes the hard-coded constant "ch4n63m3" leetspeak for "change me" whenever the operator omits replication.secret. The same secret is wired into both the client-facing SASL context and the quorum/learner SASL contexts of the embedded...