Composer: Environment Rollback Targets Exposed

The SoftwareConfig schema has been updated to include a new imageVersionRollbackTargets array. This array contains ImageVersionRollbackTarget objects, each detailing an imageVersion and its lastActiveTime (the last time the environment ran that version). These properties (imageVersion, lastActiveTime, and the imageVersionRollbackTargets array itself) are explicitly marked as readOnly and are intended for informational purposes. This is a breaking change: if your client code previously attempted to send values for these fields in create or update requests (even if they were ignored before), those requests will now fail because these properties are immutable and output-only.