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/stigmata-of-st-francis-collect.yml

@@ -12,7 +12,7 @@ text:
     faciámus.
     Qui vivis et regnas cum Deo Patre, in unitáte Spíritus Sancti, Deus, per ómnia sǽcula
     sæculórum.
-    ℟. Amen.
+    R. Amen.
   en: |
     Let us pray.
     O Lord Jesus Christ, Who, when the love of many was waxing cold, didst
@@ -24,7 +24,7 @@ text:
     repentance.
     Who livest and reignest with God the Father, in the unity of the Holy Spirit, God,
     world without end.
-    ℟. Amen.
+    R. Amen.
 status:
   la: verified
   en: verified