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-venantius-commemoration.yml

@@ -18,7 +18,7 @@ text:
     pópuli tui et præsta: ut, qui ejus mérita venerámur, fídei constántiam imitémur.
     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: |
     Ant. He that hateth his life * in this world, shall keep it unto life eternal.
     V. The righteous shall flourish like the palm tree:
@@ -30,7 +30,7 @@ text:
     godly endurance.
     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: draft
   en: draft