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/st-peter-ad-vincula-commemoration.yml

@@ -14,7 +14,7 @@ text:
     Orémus.
     Deus, qui beátum Petrum Apóstolum, a vínculis absolútum, illǽsum abíre fecísti: nostrórum, quæsumus, absólve víncula peccatórum; et ómnia mala a nobis propitiátus exclúde.
     Per 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. Thus saith the Lord unto Simon Peter: Whatsoever thou shalt bind on earth, shall be bound in heaven; and whatsoever thou shalt loose on earth, shall be loosed in heaven.
     V. They have declared the works of God:
@@ -22,7 +22,7 @@ text:
     Let us pray.
     O God, who didst loose the blessed Apostle, Peter, from his chains and didst make him go forth unharmed, loose, we pray, the chains of our sins, and in thy mercy ward off from us every evil.
     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.
+    R. Amen.
 status:
   la: draft
   en: draft