Keep native /start-work resolvable on Sisyphus, but switch the work session back to Atlas when Atlas is registered. Stamp the outgoing agent with Atlas's actual list-display key so config→start-work execution resolves correctly and still falls back to Sisyphus when Atlas is unavailable.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
YeonGyu-Kim