Normalize versicle notation to plain V./R. across propers

Unicode ℣/℟ (U+2123/U+211F) were mixed unpredictably with plain V./R.
across ~550 proper YAML files, sometimes within the same file. Screen
readers can't announce the unicode glyphs. Replace all instances with
plain text.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QC6jHsj75xcsTkapqJR6fD

src/data/propers/common/purification-commemoration.yml

@@ -11,7 +11,7 @@ text:
     fácias purificátis tibi méntibus præsentári.
     Per eúndem Dóminum nostrum Jesum Christum, Fílium tuum: qui tecum vivit et regnat in
     unitáte Spíritus Sancti, Deus, per ómnia sǽcula sæculórum.
-    ℟. Amen.
+    R. Amen.
   en: |
     Ant. The old man held his Lord * in his arms in the form of a little child, but the Child was the old man's King even that Child whom a virgin bore, and remained a virgin as before the fruit of her womb, and the God of her soul.
     V. Pray for us, holy Mother of God.
@@ -22,7 +22,7 @@ text:
     presented unto thee with pure and clean hearts.
     Through the same Jesus Christ, thy Son our Lord, Who liveth and reigneth with thee, in
     the unity of the Holy Ghost, God, world without end.
-    ℟. Amen.
+    R. Amen.
 status:
   la: verified
   en: verified