v2.3.0

Added

• Month view renders external busy intervals as pills. Events from getExternalBusy
  now appear in month day-cells as distinct, non-clickable hatched pills (timed events show
  "HH:MM label", all-day events show the label only), alongside reservation pills. Rendered
  only when a resource is selected (or auto-selected on single-resource installs) — same
  rule as the week/day availability shading.

Fixed

• CalendarView: selecting a resource emptied the calendar on Postgres installs. The
  client-side resource filter compared ids with strict ===, but Postgres serves numeric
  ids over REST while the filter value (a <select> value, or 2.2.1's single-resource
  auto-select) is a string — so 8 === '8' never matched and every reservation was hidden.
  2.2.1 made this fire with no user action on single-resource installs. Ids are now
  compared string-normalized (reservationMatchesResource / sameId, unit-tested); the
  same fix applies to the Lanes view's resource list, which had the identical mismatch.