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/guardian-angels-commemoration.yml

@@ -11,7 +11,7 @@ text:
     deféndi, et ætérna societáte gaudére.
     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. Are they not all * ministering spirits, sent forth to minister for them who shall be heirs of salvation?
     V. The Lord led the just through the right ways:
@@ -23,7 +23,7 @@ text:
     everlastingly blessed by their fellowship hereafter.
     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