Preserve shipped legacy default-agent ownership when Wizard metadata replaces the config object, and make the direct multi-agent upgrade fixture explicitly own heartbeat, system-agent, auth inheritance, fixed session storage, and ambient channels.
This keeps authored current configurations fail-closed while allowing Doctor contributions and updater restarts to consume the migrated legacy owner.
Evidence: 244 focused ownership assertions; dedicated pre-fix regression; JSON and shell fixture proof; targeted OXLint; clean structured autoreview; exact-head CI https://github.com/openclaw/openclaw/actions/runs/31691304326 (unrelated gateway shard passed on exact rerun).
This merge signs the exact reviewed r21 tree on the isolated r20 base. It does not promote, tag, publish, or release.
Peter Steinberger
b3d9bd687e