iCalendar import: translate VALARM to alerts #87
Description
Context
Per draft-ietf-calext-jscalendar-icalendar-22, the iCalendar VALARM component maps to JSCalendar alerts:
| VALARM Property | JSCalendar Alert Property |
|---|---|
| ACTION | action (DISPLAY, EMAIL only) |
| TRIGGER | trigger (offset or absolute) |
| ACKNOWLEDGED | acknowledged |
| RELATED-TO | relatedTo |
ACTION values of AUDIO or unknown types should be preserved as raw iCalendar data rather than mapped to a JSCalendar action.
Current behaviour
VALARM components nested inside VEVENT/VTODO are silently dropped during iCalendar import. No alarm/reminder data survives import.
Expected behaviour
VALARM components should be translated into alert records on the parent event or task, preserving trigger timing and action type.