propers: add February's collect and antiphon text

Real collect text for the 6 February saints that have one, plus a real
antiphon for the 2 that have one of their own — same extraction method
as January (fully-rendered live-engine output, not the raw source files'
own shorthand endings).

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

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

@@ -0,0 +1,19 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617) — read
+# directly from the reference engine's own real-date output (2029-02-24, a
+# year that date doesn't collide with a Sunday). Same convention as
+# data/propers/temporal/*-collect.yml.
+id: st-matthias-collect
+text:
+  la: |
+    Orémus.
+    Deus, qui beátum Matthíam Apostolórum tuórum collégio sociásti: tríbue, quǽsumus; ut, ejus interventióne, tuæ circa nos pietátis semper víscera 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 God, Who added blessed Matthias to the company of Thy Apostles; grant, we beseech Thee, that by his intercession we may ever be aware of the depth of Thy love for us.
+    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