Simplify bookings handlers by using bookings.total_duration_minutes, bookings.total_amount, and bookings.end_time computed columns instead of inline UNION sub-queries against booking_services/booking_custom_services. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>