Self-hosting
Upgrades
Additive contracts, expand-then-contract migrations, rolling deploys, rollback.
This page is not written yet. The rules it will state: the public API only grows and the definition
schema_version is read forever; api and worker share the schema, migrations are expand-then-contract, so deploy the role that adds capability first; old and new replicas coexist during a rolling deploy because consumers ignore unknown fields and the tables arbitrate; roll back by redeploying the previous image of the role at fault, and in an emergency set SEQ_PAUSED=1 or scale the worker to zero.