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/presentation-of-the-bvm-collect.yml

@@ -10,7 +10,7 @@ text:
     tuæ præsentári mereámur.
     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: |
     Let us pray.
     O God, Who wast pleased that the blessed Mary always a Virgin, being herself the
@@ -19,7 +19,7 @@ text:
     heavenly Temple of thy glory.
     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