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-joseph-of-cupertino-collect.yml

@@ -11,7 +11,7 @@ text:
     eum perveníre mereámur.
     Qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus, per ómnia sǽcula
     sæculórum.
-    ℟. Amen.
+    R. Amen.
   en: |
     Let us pray.
     O God, Who art pleased that thine Only-begotten Son being lifted up
@@ -21,7 +21,7 @@ text:
     be drawn up above all earthly lusts, and worthily attain unto Him.
     Who livest and reignest with him, in the unity of the Holy Spirit, God,
     world without end.
-    ℟. Amen.
+    R. Amen.
 status:
   la: verified
   en: verified