fix(calendar): OF precedence/transfer + readings resolution; EF Pentecost octave

Fixes found by validating the offline engine per-day vs the LiturgicalCalendar
API (OF) and missalemeum (EF) across 2005-2050. OF calendar is now 0 real
errors in the forward window (season/cycle already perfect).

OF precedence/transfer (calendar):
- Ash Wednesday and Holy Week Mon-Wed are band-2 privileged, so a coinciding
  feast (Chair of St Peter on Ash Wednesday) is suppressed, not observed.
- Solemnities transfer out of Holy Week / the Easter octave: the Annunciation
  defers to the Monday after the 2nd Sunday of Easter; St Joseph is anticipated
  to the Saturday before Palm Sunday; the Nativity of St John the Baptist moves
  to Jun 23 when a Lord's solemnity (Sacred Heart / Corpus Christi) falls Jun 24.
- Within a precedence band, a solemnity of the Lord/BVM outranks a saint's
  (dignity tiebreak) rather than losing an alphabetical slug tie.
- Perpetua & Felicity corrected optional -> obligatory memorial.

OF readings resolution (bible.OFRef + lectionary data):
- Verse-accurate Hebrew->Vulgate psalm mapping incl. the split psalms
  (9/10, 114/115, 116, 147); "+" verse joins and abbreviated ranges ("127-28")
  normalized; single-chapter books (2/3 John, Jude) get chapter 1.
- Cleaned harvest artifacts from of-lectionary.ini (descriptive-suffix gospels,
  "or Year A" alternates, "*"/"[Vulg.]"/bracket markers, slash abbreviations);
  Joel/Malachi/Zechariah/Esther book-versification citations fixed to Vulgate.
- Split a merged Ps 15:10/11 row in vul.tsv. Result: 0 unresolvable OF readings
  over 2557 rendered days (cycles A/B/C, varied Easters).

EF: the Octave of Pentecost (Whit Monday-Saturday) is red, not white.

1 files changed, 36 insertions, 10 deletions

diff --git a/internal/psalter/psalter.go b/internal/psalter/psalter.go
index 815f660..3e50c53 100644
--- a/internal/psalter/psalter.go
+++ b/internal/psalter/psalter.go
@@ -25,22 +25,48 @@ func DrbVerse(hebrewPsalm, lectionaryVerse int) int {
 }
 
 // HebrewToVulgateChapter maps a Masoretic psalm number to its Vulgate chapter.
+// For the split psalms (116, 147) it returns the chapter of the FIRST verse;
+// use HebrewToVulgate for the verse-accurate mapping.
 func HebrewToVulgateChapter(h int) int {
+	c, _ := HebrewToVulgate(h, 1)
+	return c
+}
+
+// HebrewToVulgate maps a Masoretic (modern) psalm number and verse to the
+// Vulgate chapter and verse. Most psalms differ only by a one-off chapter shift
+// with the verse unchanged, but four spans are joined or split, so the verse
+// carries an offset there:
+//
+//	Hebrew 9  = Vulgate 9:1-21     Hebrew 10 = Vulgate 9:22-39   (10:v -> 9:v+21)
+//	Hebrew 114 = Vulgate 113:1-8   Hebrew 115 = Vulgate 113:9-26 (115:v -> 113:v+8)
+//	Hebrew 116:1-9  = Vulgate 114  Hebrew 116:10-19 = Vulgate 115:1-10 (116:v>=10 -> 115:v-9)
+//	Hebrew 147:1-11 = Vulgate 146  Hebrew 147:12-20 = Vulgate 147:1-9  (147:v>=12 -> 147:v-11)
+func HebrewToVulgate(h, v int) (chapter, verse int) {
 	switch {
 	case h <= 8 || h >= 148:
-		return h
-	case h >= 9 && h <= 10:
-		return 9
+		return h, v
+	case h == 9:
+		return 9, v
+	case h == 10:
+		return 9, v + 21
 	case h >= 11 && h <= 113:
-		return h - 1
-	case h >= 114 && h <= 115:
-		return 113
+		return h - 1, v
+	case h == 114:
+		return 113, v
+	case h == 115:
+		return 113, v + 8
 	case h == 116:
-		return 114
+		if v <= 9 {
+			return 114, v
+		}
+		return 115, v - 9
 	case h >= 117 && h <= 146:
-		return h - 1
+		return h - 1, v
 	case h == 147:
-		return 146
+		if v <= 11 {
+			return 146, v
+		}
+		return 147, v - 11
 	}
-	return h
+	return h, v
 }