Send auth token in reserve/availability/working-hours requests so the backend can exclude the user's own reservations. Cancel old reservation via DELETE before reserving a new slot. Track reserved slot time/date for back-navigate detection. Clean up countdown interval via onDestroy and window reference to prevent duplicates. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>