New lib/caldav.js speaks CalDAV over Basic auth (shared mail account):
reads events in a window, and creates/updates/deletes iCalendar VEVENTs
with a reminder alarm. DST-correct Europe/Berlin <-> UTC handling.
Appointments (Vorstellungsgespräch / general) are managed per application
in a new "Termine" section and mirrored to the SOGo calendar; recording a
"Vorstellungsgespräch" status suggests a prefilled calendar entry
(confirm + click). A dashboard widget lists upcoming appointments. A
background poller reconciles remote edits/deletions via the collection
ctag. Config: CALDAV_URL (+ CALDAV_ALARM_MIN, CALDAV_POLL_MS); disabled
gracefully when unset.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>