Move the pending fallback, toast, and session-chain maps behind a shared controller initialized from the hook factory. This preserves the existing singleton semantics because exported helpers and hook instances still resolve the same lazily initialized controller while hook.ts stays under the 200-line limit.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
YeonGyu-Kim