propers: Benedictus antiphons for December's sanctoral entries (9/10)

4 authored fresh (Nicholas, the Immaculate Conception, Damasus, Thomas
of Canterbury), 1 corrected (Lucy -- confirmed sourced from the Roman
rite's raw [Ant 1] rather than a real Monastic 1617 rendering, same
pattern as every month so far). Thomas Apostle, Stephen Protomartyr,
John Apostle, and Holy Innocents already matched the live query as
found -- December's own late feasts (the Christmas Octave content)
turned out much less prone to the Roman/Monastic divergence than
earlier months, presumably because they're old and universal enough
that the two rites never actually diverged on them.

St. Bibiana left honestly missing: Simplex rank, Dec 2 falls within
Advent every tested year 2026-2029, same structural block as St.
Frances of Rome in March -- she can never win her own day outright
under this app's own calendar rules.

This closes out the full sweep: all 109 sanctoral entries with a
propers id have now been checked against a live Monastic query, twelve
months, one at a time. TODO.md has the final tally.

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

src/data/propers/common/st-thomas-becket-antiphon.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), Lauds
+# live query, St. Thomas of Canterbury's own day (2026-12-29). The
+# Benedictus antiphon. (He deliberately doesn't get an octave -- see
+# st-thomas-becket.yml -- but does still win his own day outright here.)
+id: st-thomas-becket-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