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-james-the-greater-commemoration.yml

@@ -14,7 +14,7 @@ text:
     Orémus.
     Esto, Dómine, plebi tuæ sanctificátor et custos: ut, Apóstoli tui Jacóbi muníta præsídiis, et conversatióne tibi pláceat, et secúra mente desérviat.
     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. Ye who have left all things, and have followed me, shall receive an hundredfold, and shall possess life everlasting.
     V. They have declared the works of God:
@@ -22,7 +22,7 @@ text:
     Let us pray.
     Be Thou thyself, O Lord, the Sanctifier and the Shepherd of thy people, that we who are overshadowed by the help of thine Apostle James may, in our conversation, walk with thee, and in all quietness of spirit serve 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.
+    R. Amen.
 status:
   la: draft
   en: draft