propers: Benedictus antiphons for January's sanctoral entries (9/9)

All 9 January saints with a propers id: 5 authored fresh (Marcellus I,
Paul the Hermit, Fabian & Sebastian, Vincent & Anastasius, John
Chrysostom), 3 corrected (Chair of St. Peter at Rome, Agnes,
Conversion of St. Paul -- each confirmed sourced from the Roman rite's
raw [Ant 1] rather than a real Monastic 1617 rendering, same mistake
as St. Lawrence's earlier fix), 1 left honestly missing (Hilary of
Poitiers -- this app's calendar has him Jan 23, but Divinum Officium's
own calendar has him Jan 14; flagged in TODO.md rather than guessed
at). See TODO.md for the full remaining scope and the method this
settled on after automated matching proved unreliable on real edge
cases (shared dates, saints the reference engine doesn't carry at
all).

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

src/data/propers/common/st-marcellus-i-antiphon.yml

@@ -0,0 +1,10 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), Lauds
+# live query, St. Marcellus I's own day (2026-01-16). The Benedictus
+# antiphon.
+id: st-marcellus-i-antiphon
+text:
+  la: "Qui odit * ánimam suam in hoc mundo, in vitam ætérnam custódit eam."
+  en: "He that hateth his life * in this world, shall keep it unto life eternal."
+status:
+  la: verified
+  en: verified