The calendar view hides employees whose contract doesn't intersect the displayed
month, but the absence PDF print still listed them. Apply the same intersection
filter (hasContractInRange over [from, to]) in AbsencePrintProvider, and reject
invalid from/to dates. A employee who left in April no longer appears on a May print.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
