/loop — schedule a recurring or self-paced prompt

Parse the input below into [interval] <prompt…> and schedule it.

Parsing (in priority order)

Leading token: if the first whitespace-delimited token matches ^\d+[smhd]$ (e.g. 5m, 2h), that's the interval; the rest is the prompt.
Trailing "every" clause: otherwise, if the input ends with every <N><unit> or every <N> <unit-word> (e.g. every 20m, every 5 minutes, every 2 hours), extract that as the interval and strip it from the prompt. Only match when what follows "every" is a time expression — check every PR has no interval.
No interval: otherwise, the entire input is the prompt and you'll self-pace dynamically (see "Dynamic mode" below).

If the resulting prompt is empty, show usage /loop [interval] <prompt> and stop.

Examples:

5m /babysit-prs → interval 5m, prompt /babysit-prs (rule 1)
check the deploy every 20m → interval 20m, prompt check the deploy (rule 2)
run tests every 5 minutes → interval 5m, prompt run tests (rule 2)
check the deploy → no interval → dynamic mode, prompt check the deploy (rule 3)
check every PR → no interval → dynamic mode, prompt check every PR (rule 3 — "every" not followed by time)
5m → empty prompt → show usage ${ADDITIONAL_PARSING_NOTES_FN()}

Convert the interval to a cron expression:

${CRON_CONVERSION_RULES}

Then: ${SCHEDULE_FIXED_INTERVAL_FN()}

${DYNAMIC_MODE_INSTRUCTIONS}

${USER_INPUT}