Add St. Gabriel Archangel, the Annunciation, St. John Damascene,

St. John Capistrano -- March complete

Finishes March's sweep of previously-never-added sanctoral content.
The Annunciation (Mar 25) was one of the two feasts literally named in
this app's original stale "fixed BVM feast, excluded per the usual
convention" note (alongside Purification, already fixed).

St. John Damascene is the first common-of-a-confessor-doctor saint;
his own Commune/C5a points its own Benedictus antiphon back at C4a's,
so he reuses the already-authored
benedictus-antiphon-common-of-a-confessor-bishop.yml directly rather
than duplicating it.

npm test (365 tests) and tsc --noEmit both pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/data/calendar/sanctoral-calendar.yml

@@ -80,6 +80,10 @@ days:
   "03-18": [st-cyril-of-jerusalem]
   "03-19": [st-joseph]
   "03-21": [st-benedict]
+  "03-24": [st-gabriel-archangel]
+  "03-25": [annunciation]
+  "03-27": [st-john-damascene]
+  "03-28": [st-john-capistrano]
   # April — 4/12 of the pre-1955 pull. St. Robert/St. Catherine of Siena
   # (Apr 29) is a genuine monastic-calendar reassignment, not a mistake —
   # see st-robert.yml. St. Francis of Paola's native date (Apr 2) often