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-pius-x-collect.yml

@@ -10,7 +10,7 @@ text:
     exémpla sectántes, prǽmia consequámur ætérna.
     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 to safeguard Catholic faith and to restore all things in
@@ -19,7 +19,7 @@ text:
     his ordinances and to follow his example, we may reap eternal rewards.
     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