* feat(cron): enhance CronService with wake channel and improve job scheduling logic
* fix(cron): update file permission mode to use octal notation in test and fix some lint errors
* fix(cron): improve wake channel handling and enhance concurrency in tests
- write config and cron store with 0600 instead of 0644
- check allow list in Slack slash commands and app mentions
- pass workspace restrict flag to cron exec tool
Closes#179