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-william-abbot-collect.yml

@@ -7,12 +7,12 @@ text:
     Orémus.
     Deus, qui infirmitáti nostræ ad teréndam salútis viam in Sanctis tuis exémplum et præsídium collocásti: da nobis, ita beáti Guliélmi abbátis mérita venerári; ut ejúsdem excipiámus suffrágia, et vestígia prosequámur.
     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 made Your Saints an example and a help for our weakness; grant us, as we walk the path of salvation, so to venerate the virtues of the blessed Abbot William that we may obtain his intercession and follow in his footsteps.
     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