Add full Gospel pericopes to Advent/Christmas Sunday Matins readings

Nocturn 3 previously dropped the bare "Et réliqua" Gospel incipit and
kept only the patristic homily, so the Gospel citation and text never
appeared. Authors the full pericope before the homily for advent-1
through advent-4 and christmas-octave-sunday, sourced from the
reference engine's Missale Gospel files. Authoring Advent 4's Gospel
surfaces a genuine second Matins Gospel on the rare Dec-24-as-Advent-4
collision (2023/2028), so the affected test now expects both readings
instead of one.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AGjUyhUZJaSjiniEmnLdak

src/data/propers/nocturn-readings/advent-3.yml

@@ -12,6 +12,14 @@
 # pattern as advent-1/-2. Combined Lectio7's homily portion (incipit
 # dropped) with Lectio8-9, using Responsory7 ("Veni, Dómine, et noli
 # tardáre").
+#
+# Update (2026-09): the Gospel pericope itself, previously left unauthored
+# per the "bare incipit, skip it" convention described above, is now
+# authored too (isGospel: true, immediately before the homily) - sourced
+# from the Missale's own [Evangelium] for the same Sunday (the Mass Gospel
+# and the Matins Nocturn 3 Gospel are the same pericope), not guessed at.
+# Matins now shows the full Gospel, then the homily on it, matching
+# post-pentecost-15's original pattern - see TODO.md's dated entry.
 id: advent-3
 readings:
   - nocturn: 2
@@ -69,6 +77,16 @@ readings:
       en: "R. Weep not, O Egypt, for the Ruler cometh unto thee, and the depths shall be moved at His presence. * To deliver His people out of the hand of the mighty.\nV. Behold, the Lord of hosts, thy God, cometh with great power.\nR. To deliver His people out of the hand of the mighty."
     status: { la: verified, en: verified }
 
+  - nocturn: 3
+    isGospel: true
+    citation: { la: "Joann 1:19-28", en: "John 1:19-28" }
+    text:
+      la: >-
+        In illo témpore: Misérunt Judǽi ab Jerosólymis sacerdótes et levítas ad Joánnem, ut interrogárent eum: Tu quis es? Et conféssus est, et non negávit: et conféssus est: Quia non sum ego Christus. Et interrogavérunt eum: Quid ergo? Elías es tu? Et dixit: Non sum. Prophéta es tu? Et respondit: Non. Dixérunt ergo ei: Quis es, ut respónsum demus his, qui misérunt nos? Quid dicis de te ipso? Ait: Ego vox clamántis in desérto: Dirígite viam Dómini, sicut dixit Isaías Prophéta. Et qui missi fúerant, erant ex pharisǽis. Et interrogavérunt eum, et dixérunt ei: Quid ergo baptízas, si tu non es Christus, neque Elías, neque Prophéta? Respóndit eis Joánnes, dicens: Ego baptízo in aqua: médius autem vestrum stetit, quem vos nescítis. Ipse est, qui post me ventúrus est, qui ante me factus est: cujus ego non sum dignus ut solvam ejus corrígiam calceaménti. Hæc in Bethánia facta sunt trans Jordánem, ubi erat Joánnes baptízans.
+      en: >-
+        At that time, the Jews sent to John from Jerusalem priests and Levites to ask him, Who are you? And he acknowledged and did not deny; and he acknowledged, I am not the Christ. And they asked him, What then? Are you Elias? And he said, I am not. Are you the Prophet? And he answered, No. They therefore said to him, Who are you? that we may give an answer to those who sent us. What have you to say of yourself? He said, I am the voice of one crying in the desert, 'Make straight the way of the Lord,' as said Isaias the prophet. And they who had been sent were from among the Pharisees. And they asked him, and said to him, Why, then, do you baptize, if you are not the Christ, nor Elias, nor the Prophet? John said to them in answer, I baptize with water; but in the midst of you there has stood One Whom you do not know. He it is Who is to come after me, Who has been set above me, the strap of Whose sandal I am not worthy to loose. These things took place at Bethany, beyond the Jordan, where John was baptizing.
+    status: { la: verified, en: verified }
+
   - nocturn: 3
     isGospel: false
     source: "Pope St. Gregory the Great, Homily 7 on the Gospels"