One small part per post: a probe, a daily job, a trick, a trap that cost an afternoon.
Scheduled jobs on a Mac belong in a launchd plist: they survive reboots, run as your user, and log where you can find them. One minimal plist, the commands to load it, and the privacy gotcha that makes a job under Documents fail with Operation not permitted.
launchctl kickstart -k restarts a launchd job with the configuration it already has in memory. Edit the plist, kickstart, and the service comes back running the old settings while looking freshly restarted. How it bites and the two lines that fix it.
