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-gregory-the-great-collect.yml

@@ -8,12 +8,12 @@ text:
     Orémus.
     Deus, qui ánimæ fámuli tui Gregórii ætérnæ beatitúdinis prǽmia contulísti: concéde propítius; ut, qui peccatórum nostrórum póndere prémimur, ejus apud te précibus sublevémur.
     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 hast blessed the soul of thy servant Gregory with an everlasting blessing, mercifully grant that we, who groan under the burden of our sins, may by his prayers be relieved.
     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