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-thomas-becket-commemoration.yml

@@ -14,7 +14,7 @@ text:
     Orémus.
     Deus, pro cujus Ecclésia gloriósus Póntifex Thomas gládiis impiórum occúbuit: præsta, quǽsumus; ut omnes, qui ejus implórant auxílium, petitiónis suæ salutárem consequántur efféctum.
     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. He that hateth his life * in this world, shall keep it unto life eternal.
     V. The righteous shall flourish like the palm tree:
@@ -22,7 +22,7 @@ text:
     Let us pray.
     O God, in defence of Whose Church the glorious Bishop Thomas fell by the swords of wicked men, grant, we beseech thee, that all that ask his help, may obtain wholesome fruit of their petition.
     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