Prepend R. to nocturn-readings responsories missing their opening marker

All 53 nocturn-readings files with a responsory field started straight
into the text with no leading R., unlike octave-readings' own R./V.
convention. Fixed in content per direct instruction (not injected at
render time), matching each file's own existing plain V./R. style rather
than switching to octave-readings' R./V. glyphs.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EWzE3kaSZCs79fPBrrE1aF

src/data/propers/nocturn-readings/post-pentecost-10.yml

@@ -61,8 +61,8 @@ readings:
         water, and our whole race perished, save eight persons? Was it not God, and none other, Which
         brought upon them all these things, and more also?
     responsory:
-      la: "Percússit Saul mille, et David decem míllia: * Quia manus Dómini erat cum illo: percússit Philisthǽum, et ábstulit oppróbrium ex Israël.\nV. Nonne iste est David, de quo canébant in choro, dicéntes: Saul percússit mille, et David decem míllia?\nR. Quia manus Dómini erat cum illo: percússit Philisthǽum, et ábstulit oppróbrium ex Israël."
-      en: "Saul hath slain his thousands, and David his ten thousands. * Because the hand of the Lord was with him, he smote the Philistine, and took away the reproach from Israel.\nV. Is not this David? Did they not sing one to another of him in dances, saying: Saul hath slain his thousands, and David his ten thousands?\nR. Because the hand of the Lord was with him, he smote the Philistine, and took away the reproach from Israel."
+      la: "R. Percússit Saul mille, et David decem míllia: * Quia manus Dómini erat cum illo: percússit Philisthǽum, et ábstulit oppróbrium ex Israël.\nV. Nonne iste est David, de quo canébant in choro, dicéntes: Saul percússit mille, et David decem míllia?\nR. Quia manus Dómini erat cum illo: percússit Philisthǽum, et ábstulit oppróbrium ex Israël."
+      en: "R. Saul hath slain his thousands, and David his ten thousands. * Because the hand of the Lord was with him, he smote the Philistine, and took away the reproach from Israel.\nV. Is not this David? Did they not sing one to another of him in dances, saying: Saul hath slain his thousands, and David his ten thousands?\nR. Because the hand of the Lord was with him, he smote the Philistine, and took away the reproach from Israel."
     status: { la: verified, en: verified }
 
   - nocturn: 3
@@ -119,6 +119,6 @@ readings:
         his breast, saying "Lord, be merciful to me a sinner." Hearken here to a prayer and wonderest
         thou that when the sinner remembereth, God forgetteth.
     responsory:
-      la: "Duo Séraphim clamábant alter ad álterum: * Sanctus, sanctus, sanctus Dóminus Deus Sábaoth: * Plena est omnis terra glória ejus.\nV. Tres sunt qui testimónium dant in cælo: Pater, Verbum, et Spíritus Sanctus: et hi tres unum sunt.\nR. Plena est omnis terra glória ejus."
-      en: "One Seraph cried unto another: * Holy, Holy, Holy is the Lord God of hosts; * The whole earth is full of His glory.\nV. There are Three That bear record in heaven: the Father, the Word, and the Holy Ghost, and these Three are One.\nR. The whole earth is full of His glory."
+      la: "R. Duo Séraphim clamábant alter ad álterum: * Sanctus, sanctus, sanctus Dóminus Deus Sábaoth: * Plena est omnis terra glória ejus.\nV. Tres sunt qui testimónium dant in cælo: Pater, Verbum, et Spíritus Sanctus: et hi tres unum sunt.\nR. Plena est omnis terra glória ejus."
+      en: "R. One Seraph cried unto another: * Holy, Holy, Holy is the Lord God of hosts; * The whole earth is full of His glory.\nV. There are Three That bear record in heaven: the Father, the Word, and the Holy Ghost, and these Three are One.\nR. The whole earth is full of His glory."
     status: { la: verified, en: verified }