test(scheduling): add exhaustive blocker, gap, and cross-day tests
Add comprehensive time blocker tests: multiple blockers, blocker+booking combination, all-day, non-overlapping, multi-day, boundary start/end, out-of-hours, recurring (cron), reservation, overlapping, adjacent, cross-day midnight, closed days, exceptional hours. Add subtractTimeSlots and normalizeTime unit tests.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
popertotsandSisyphus
7756f3af96