Add name history cleanup to the scheduling pipeline and improve time blocker tests. - Call CleanupOldNameHistory from GetAvailableHours to periodically purge old name_history entries (6+ months) - Add time_blockers_test.go with comprehensive test coverage - Update time-blockers.go with name_history cleanup logic Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>