Remove debug logging from `collect_triggers` and
`separate_master_and_recurrence`, and add full alarm rendering support:
convert `Timedesc.Span.t` triggers to `++n`/`WARN`/`+n`/`SCHED` remind
syntax for both all-day and timed events, with dynamic `FSET` generation
for multiple triggers and annotated `MSG` bodies showing advance notice.