Import standard iCalendar event files into SchedPlus

[ZFordDev]

Goal

Allow users to bring events from Google Calendar, Apple Calendar, Outlook, and other planners into SchedPlus without manually recreating them. The first implementation should use the open iCalendar file format and remain fully offline.

Scope

• Accept local .ics files containing VEVENT records.
• Map supported event fields to SchedPlus tasks with an explicit, documented policy.
• Handle timed events, all-day events, timezones, descriptions, categories, and durations.
• Present a preview and summary before committing an import.
• Define duplicate detection and unsupported recurrence behavior.
• Preserve existing SchedPlus JSON import as a separate native data-transfer format.

Acceptance criteria

• Representative Google Calendar and Apple Calendar exports import correctly.
• Import never requires an account or network connection.
• Timezone conversion and local wall-clock behavior are covered by tests.
• Duplicate and unsupported records are reported without partial silent loss.
• Users can cancel before any database change.
• Repository and DocsHub guides document supported fields and limitations.