Merge branch 'engine-precedence-fixes': OF/EF calendar+readings flawlessness pass

Per-day validation vs litcal (OF) and missalemeum (EF) 2005-2050, all defects
fixed and re-validated to zero: OF calendar 0 real errors forward, OF readings
0 unresolvable, EF 0 reading gaps + resumed Sundays correct.

1 files changed, 17 insertions, 3 deletions

diff --git a/internal/calendar/temporal.go b/internal/calendar/temporal.go
index b0dc653..1c8d74f 100644
--- a/internal/calendar/temporal.go
+++ b/internal/calendar/temporal.go
@@ -117,6 +117,15 @@ func ferialDay(season Season, slug string, col Colour, week int, privFeria bool)
 		Cel: Celebration{Slug: slug, Rank: RankFerial, Colour: col, Layer: "temporal"}}
 }
 
+// privFerialDay builds a band-2 privileged weekday (Ash Wednesday, Holy Week
+// Monday-Wednesday): a ferial no sanctoral feast or memorial can displace (only
+// a solemnity may, and solemnities transfer off it -- Table of Liturgical Days
+// #2). Distinct from ferialDay's PrivFeria (band 9) Lenten/Advent weekdays.
+func privFerialDay(season Season, slug string, col Colour, week int) temporalDay {
+	return temporalDay{Season: season, Colour: col, Week: week, Rank: RankFerial, Privileged: true,
+		Cel: Celebration{Slug: slug, Rank: RankFerial, Colour: col, Layer: "temporal"}}
+}
+
 // temporal computes the temporal identity of date under the given Selection.
 func temporal(date time.Time, sel Selection) temporalDay {
 	date = date.UTC().Truncate(24 * time.Hour)
@@ -180,11 +189,16 @@ func temporal(date time.Time, sel Selection) temporalDay {
 		if sun {
 			return sundayDay(Lent, "palm-sunday", Red, 6)
 		}
-		return ferialDay(Lent, "holy-week-"+weekdayAbbr(wd), Violet, 6, true)
+		// Holy Week Mon-Wed are band-2 privileged: no feast/memorial is kept.
+		return privFerialDay(Lent, "holy-week-"+weekdayAbbr(wd), Violet, 6)
 
 	case !date.Before(ashWed) && date.Before(palmSunday): // Lent
-		if !date.Before(ashWed) && date.Before(ashWed.AddDate(0, 0, 4)) {
-			// Ash Wednesday through the Saturday after (before Lent I).
+		if sameDay(date, ashWed) {
+			// Ash Wednesday is band-2 privileged (suppresses any coinciding feast).
+			return privFerialDay(Lent, "lent-after-ashes-wed", Violet, 0)
+		}
+		if date.Before(ashWed.AddDate(0, 0, 4)) {
+			// Thursday-Saturday after Ash Wednesday (before Lent I): band-9 privileged.
 			return ferialDay(Lent, "lent-after-ashes-"+weekdayAbbr(wd), Violet, 0, true)
 		}
 		lent1 := nextWeekday(ashWed, time.Sunday)