Deploy the calendar viewer to beryllium alongside the rest of Omni.Web.
- Add iCalendar dep to Haskell.nix
- Wire /cal route into Omni.Web.Core
- Configure CALENDARS_PATH env var (or default to /home/ben/Calendars)
- Ensure vdirsyncer service is running on beryllium so the filesystem data is fresh
- ship.sh deployment
Ava verified: commit found in live history referencing this task/feature. Moving to Verified.