fix(of): partial-proper memorials compose proper part + ferial (match USCCB)

A memorial marked 'PROPER Gospel' (Guardian Angels, Mary Magdalene, Our Lady of
Sorrows, Joseph the Worker, the Passion of John the Baptist, Sts Martha/Mary/
Lazarus) uses the FERIAL first reading + its proper gospel; one marked 'PROPER
First Reading' (Barnabas) uses its proper first + the ferial gospel. Previously we
imported catholic-resources' *suggested* first for the gospel-proper ones, which
differs from what USCCB publishes.

- readings.go: when the observed's inline Mass has only a proper gospel (or only a
  proper first), fill the missing reading/psalm from the day's ferial and sort into
  canonical order. A fully-proper feast is untouched. Factored out ofFerial().
- gen-of-sanctoral-readings.py: keep only the strictly-proper part per the CR
  source-note.

Verified vs USCCB: Guardian Angels (2025-10-02) now = Nehemiah 8 / Ps 19 /
Matt 18:1-5,10 exactly. Updates TestUniversalSanctoralReadings.

1 files changed, 35 insertions, 8 deletions

diff --git a/internal/caldata/readings.go b/internal/caldata/readings.go
index 49109f5..1b87b7a 100644
--- a/internal/caldata/readings.go
+++ b/internal/caldata/readings.go
@@ -1,11 +1,25 @@
 package caldata
 
 import (
+	"sort"
 	"time"
 
 	"github.com/lukaszkasprzak/lectio/internal/calendar"
 )
 
+var partOrder = map[string]int{"first": 0, "psalm": 1, "second": 2, "acclamation": 3, "gospel": 4}
+
+// ofFerial returns the day's Ordinary-Form ferial (weekday) readings, or nil.
+func ofFerial(sel calendar.Selection, date time.Time, day calendar.LiturgicalDay) []calendar.Reading {
+	if day.WeekdayCycle == "" || date.Weekday() == time.Sunday {
+		return nil
+	}
+	if temp := calendar.Compute(date, sel, nil); temp.Observed.Layer == "temporal" {
+		return TemporalReadings("new", temp.Observed.Slug+"-"+day.WeekdayCycle)
+	}
+	return nil
+}
+
 // Readings resolves a day's Mass readings: the observed celebration's inline
 // propers, else the temporal lectionary for its slug, else -- for an EF
 // weekday with no proper Mass -- the preceding Sunday's Mass (the 1962 rule
@@ -17,6 +31,24 @@ func Readings(sel calendar.Selection, layers []calendar.Layer, date time.Time, d
 		rs = append(rs, m.Readings...)
 	}
 	if len(rs) > 0 {
+		// OF: a memorial with only a PROPER gospel (or only a proper first) takes
+		// the missing reading from the day's ferial -- e.g. the Guardian Angels are
+		// the ferial first reading + their proper gospel (Matt 18), and St Barnabas
+		// is his proper first (Acts 11) + the ferial gospel. A fully-proper feast
+		// (first AND gospel present) is left untouched.
+		have := map[string]bool{}
+		for _, r := range rs {
+			have[r.Part] = true
+		}
+		if sel.Form != "old" && !(have["first"] && have["gospel"]) {
+			for _, fr := range ofFerial(sel, date, day) {
+				if p := fr.Part; !have[p] && (p == "first" || p == "psalm" || p == "gospel") {
+					rs = append(rs, fr)
+					have[p] = true
+				}
+			}
+			sort.SliceStable(rs, func(i, j int) bool { return partOrder[rs[i].Part] < partOrder[rs[j].Part] })
+		}
 		return rs
 	}
 	// temporal table: EF by bare slug; OF by slug+cycle. Sundays & solemnities
@@ -39,14 +71,9 @@ func Readings(sel calendar.Selection, layers []calendar.Layer, date time.Time, d
 	}
 	// OF: a sanctoral memorial / optional memorial with no proper readings of its
 	// own reads the FERIAL (weekday) readings of the day -- the ordinary OF rule.
-	// Compute the pure temporal (no sanctoral) to get the day's ferial slug.
-	if sel.Form != "old" && day.Observed.Layer != "temporal" &&
-		day.WeekdayCycle != "" && date.Weekday() != time.Sunday {
-		temp := calendar.Compute(date, sel, nil)
-		if temp.Observed.Layer == "temporal" {
-			if r := TemporalReadings("new", temp.Observed.Slug+"-"+day.WeekdayCycle); len(r) > 0 {
-				return r
-			}
+	if sel.Form != "old" && day.Observed.Layer != "temporal" {
+		if r := ofFerial(sel, date, day); len(r) > 0 {
+			return r
 		}
 	}
 	// EF: a green-season weekday with no proper Mass repeats the preceding Sunday.