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-gertrude-collect.yml

@@ -10,7 +10,7 @@ text:
     cleménter abstérge, et ejúsdem tríbue gaudére consórtio.
     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: |
     Let us pray.
     O God, Who didst make unto thyself a pleasant dwelling-place in the
@@ -20,7 +20,7 @@ text:
     rejoice with her in thy presence.
     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: verified
   en: verified