mcp-caldav

Merge origin/main: pull in project README and richer CLAUDE.md

Add a justfile for common operations

Anchor list_events range to a local timezone; gate dump_raw_calendar_data behind a cargo feature

Scope master-RRULE lookup to VEVENT blocks; skip VTIMEZONE RRULEs

Anchor RRULE expansion to original TZID so DST transitions land correctly