Approved App artifacts can be checked against a new runtime with unchanged SDK dependencies. Compatibility requires fresh platform and database contract checks; the original approval and artifact remain unchanged.

Apps may declare contract migrations in database/tenant-migration-phases.json using migration names without .php. Expansion runs before switching; contract changes run only after the previous runtime has retired. Apps without this declaration keep their existing behavior. No SDK upgrade is required.

The administrator Console can link a stopped deployment to corrected published versions. Original evidence and completed tenant work are retained; unresolved operations or changed completed targets block continuation.