propers: add December's collect and antiphon text

10 collects, 5 antiphons -- including backfilling the pre-existing
Immaculate Conception entry. St. Damasus's collect is Latin-only (no
English translation exists in the reference source at all); a few
others (All Saints, Bibiana, Immaculate Conception) needed their English
read directly from the raw source file after the live query's English
side either omitted the Oratio translation or rendered the wrong Marian
feast's text -- caught by cross-checking, not assumed.

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

src/data/propers/common/holy-innocents-antiphon.yml

@@ -0,0 +1,9 @@
+# Verified against Divinum Officium (Latin/English Sancti/12-28.txt's own
+# [Ant 1] — the Lauds-hour antiphon, not Terce's.
+id: holy-innocents-antiphon
+text:
+  la: "Hi sunt, * qui cum muliéribus non sunt coinquináti: vírgines enim sunt, et sequúntur Agnum quocúmque íerit."
+  en: "These are they * who were not defiled with women; for they are virgins, and follow the Lamb whithersoever he goeth."
+status:
+  la: verified
+  en: verified