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/lauds-versicle-purification.yml

@@ -5,11 +5,11 @@
 id: lauds-versicle-purification
 text:
   la: |
-    ℣. Diffúsa est grátia in lábiis tuis.
-    ℟. Proptérea benedíxit te Deus in ætérnum.
+    V. Diffúsa est grátia in lábiis tuis.
+    R. Proptérea benedíxit te Deus in ætérnum.
   en: |
-    ℣. Grace is poured into thy lips.
-    ℟. Therefore God hath blessed thee for ever.
+    V. Grace is poured into thy lips.
+    R. Therefore God hath blessed thee for ever.
 status:
   la: verified
   en: verified