propers: add January's collect and antiphon text

Real collect text for the 9 January saints that have one, plus a real
antiphon for the 3 that have one of their own (as opposed to falling back
to a generic Common-of-Saints text) — read directly from the reference
engine's fully-rendered output, not reconstructed from the raw source
files' own shorthand endings ($Per Dominum, $Qui vivis, etc.).

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

src/data/propers/common/st-agnes-collect.yml

@@ -0,0 +1,19 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617) — read
+# directly from the reference engine's own real-date output (2029-01-21, a
+# year that date doesn't collide with a Sunday). Same convention as
+# data/propers/temporal/*-collect.yml.
+id: st-agnes-collect
+text:
+  la: |
+    Orémus.
+    Omnípotens sempitérne Deus, qui infírma mundi éligis, ut fórtia quæque confúndas: concéde propítius; ut, qui beátæ Agnétis Vírginis et Mártyris tuæ solémnia cólimus, ejus apud te patrocínia sentiámus.
+    Per Dóminum nostrum Jesum Christum, Fílium tuum: qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus, per ómnia sǽcula sæculórum.
+    ℟. Amen.
+  en: |
+    Let us pray.
+    O Almighty and everlasting God, Who hast chosen the weak things of the world to confound the things which are mighty, mercifully grant unto us that we who keep the solemn feast of thy blessed Virgin and Martyr Agnes, may feel the power of her intercession with thee.
+    Through Jesus Christ, thy Son our Lord, Who liveth and reigneth with thee, in the unity of the Holy Ghost, God, world without end.
+    ℟. Amen.
+status:
+  la: verified
+  en: verified