Convert all server/, test, and setup files from require()/module.exports
to import/export syntax. Activate ESM globally via "type": "module" in
package.json and load dotenv via --import dotenv/config in npm scripts.
Root causes:
1. parseRRule did not strip the "RRULE:" prefix stored by the ICS parser,
causing all recurrence rules from CalDAV sync to silently fail parsing
2. YEARLY frequency (used by birthday events) was not supported
3. expandRecurringEvents filtered instances only by start date, missing
multi-day events that start before the view window but span into it
4. All-day recurring instances got datetime end values instead of date-only
Fixes#5 (follow-up from @tschig)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Ulas