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/immaculate-conception-commemoration.yml

@@ -8,7 +8,7 @@ text:
     Orémus.
     Deus, qui per immaculátam Vírginis Conceptiónem dignum Fílio tuo habitáculum præparásti: quǽsumus; ut qui ex morte ejúsdem Fílii tui prævísa, eam ab omni labe præservásti, nos quoque mundos ejus intercessióne ad te perveníre concédas.
     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. Let us this day keep solemnly the Conception of Mary, Mother but still Maiden, a step toward the loftiness of her throne. Alleluia.
     V. Pray for us, holy Mother of God.
@@ -16,7 +16,7 @@ text:
     Let us pray.
     O God, by the Immaculate Conception of the Virgin, thou prepared a worthy habitation for thy Son; we beseech thee, that, as by the foreseen death of thy same Son thou preserved her from all stain of sin, so thou would grant us also, through her intercession, to come to thee with pure hearts.
     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