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-therese-of-lisieux-commemoration.yml

@@ -19,7 +19,7 @@ text:
     consequámur ætérna.
     Qui vivis et regnas cum Deo Patre, in unitáte Spíritus Sancti, Deus, per ómnia sǽcula
     sæculórum.
-    ℟. Amen.
+    R. Amen.
   en: |
     Ant. The kingdom of heaven is like unto a merchantman * seeking goodly pearls, who, when he had found one pearl of great price, went and sold all that he had, and bought it.
     V. Grace is poured into thy lips.
@@ -31,7 +31,7 @@ text:
     Theresa, that we may attain to an everlasting reward.
     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