Lower Matins 3-nocturn threshold from Duplex to Semiduplex

Semiduplex and Duplex should share the same 3-nocturn/3-psalms-each
shape (distinct from Sunday/Duplex-majus+'s 6/6/3-plus-canticles
scheme) — the previous Duplex floor meant a Semiduplex winner like
St. Stephen of Hungary wrongly fell all the way through to the
1-nocturn ferial branch.

New threshold is a separate check from isDoubleOrHigher, which drives
the unrelated antiphon-doubling rule elsewhere and stays floored at
Duplex — the two thresholds only coincided by accident before this
change. No new content authoring was needed: ferialPsalmodyThreeNocturns
already chunks the ferial 9-psalm pool into 3/3/3 as the fallback for
a plain-Duplex winner with no override authored, and Semiduplex
winners now route into that same already-working branch.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X26BkFT3ARbtUGXuBmzUmD

TODO.md

@@ -4838,3 +4838,41 @@ category of move as this app's existing late-canonization rank-deflation convent
 the other direction — bringing his own count to 6.
 
 `npm test` (821 passed), `tsc --noEmit`, and `npm run build` all pass.
+
+### Matins ferial nocturn: mid-nocturn versicle removed, a real live-verified bug (2026-09-02)
+
+User noticed the 1-nocturn ferial branch had a V./R. versicle stuck mid-list as if marking a
+nocturn boundary — structurally incoherent for a single continuous nocturn.
+
+`data/hours/matins-ferial-antiphons.yml`'s per-weekday `groups` carried a `versicle` field
+ported from a mid-list V./R. line embedded in the source `Psalmi matutinum.txt`
+(`[Daym1_]`-`[Daym6_]`), rendered partway through the single continuous 1-nocturn ferial day.
+Live-verified against the reference engine (`Pofficium.pl`, `command=prayMatutinum`,
+`version=Monastic Tridentinum 1617`) for Wednesday and Thursday: the real office runs straight
+from the last psalm to the Capitulum, no versicle anywhere in the psalmody — that source line
+is inert there, never actually emitted. Removed the field from all 6 weekdays and the
+rendering code (`ferialAntiphonedNocturn`); the earlier "versicle placement" reasoning in that
+file's header was a documented-but-unverified assumption, not real content.
+
+See memory `vu_ferial_matins_antiphons` for full detail.
+
+`npm test`, `tsc --noEmit`, and `npm run build` all pass.
+
+### Matins: 3-nocturn threshold lowered from Duplex to Semiduplex (2026-09-02)
+
+Same session, a separate fix: the 3-nocturn gate (`hours/matins.ts`'s `threeNocturns`) was
+floored at Duplex (`isDoubleOrHigher`). User's own design call, prompted by noticing today's
+Matins (St. Stephen of Hungary, Semiduplex) wrongly rendering as 1-nocturn: Semiduplex and
+Duplex should share the same 3-nocturn/3-psalms-each shape (distinct from Sunday/Duplex-majus
++'s 6/6/3-plus-canticles scheme). Lowered the floor with a new, separate check
+(`isAtLeast(winner.rank, 'semiduplex')`) rather than touching `isDoubleOrHigher` itself, which
+drives an unrelated antiphon-doubling rule elsewhere and must stay floored at Duplex. No new
+content authoring was needed — `ferialPsalmodyThreeNocturns` already existed and already
+chunks the ferial 9-psalm pool into 3/3/3 as the fallback for a plain-Duplex winner with no
+override authored; Semiduplex winners now fall into that same already-working branch. Proved
+via St. Stephen of Hungary (2026-09-02, Common of a Confessor): 3 real nocturns, Common's own
+Terce/Sext/None antiphons+versicles, Te Deum present.
+
+See memory `vu_matins_semiduplex_threshold` for full detail.
+
+`npm test` (823 passed), `tsc --noEmit`, and `npm run build` all pass.

src/data/hours/matins-ferial-antiphons.yml

@@ -1,7 +1,8 @@
-# Antiphons + versicles for the plain ferial weekday Matins nocturn (no
+# Antiphons for the plain ferial weekday Matins nocturn (below Semiduplex,
-# Sunday, no Duplex+ override) — previously rendered with bare psalms and
+# see hours/matins.ts's threeNocturns threshold) — previously rendered
-# no antiphon at all (a genuine oversight, not a documented design choice
+# with bare psalms and no antiphon at all (a genuine oversight, not a
-# like `ferialPsalmodyThreeNocturns`'s antiphon-less fallback).
+# documented design choice like `ferialPsalmodyThreeNocturns`'s
+# antiphon-less fallback).
 #
 # `psalter-distribution.yml`'s own `matins:` table is NOT the historical
 # per-weekday psalm set — its own header documents a deliberate "editorial
@@ -43,16 +44,17 @@
 # psalm, just spread over two verse ranges); any cross-psalm pair is now
 # split per the "One antiphon per psalm" note above.
 #
-# Versicle placement: each weekday draws its 9 psalms from 1-2 different
+# No mid-nocturn versicle (fixed 2026-09-02): the source `Psalmi
-# original source days (see each weekday's own comment below for exactly
+# matutinum.txt` files (`[Daym1_]`-`[Daym6_]`) embed a V./R. line partway
-# which), but only one versicle fits per plain single-nocturn weekday —
+# through each weekday's psalm list, and an earlier version of this file
-# taken from whichever source day contributes the majority of that
+# ported it as a real `versicle` field on the group where it happened to
-# weekday's psalms, placed at the same relative position it held in that
+# fall, rendered mid-nocturn as if marking a nocturn boundary. Live-verified
-# source day's own sequence (immediately after whichever group of this
+# against the reference engine (`Pofficium.pl`, `command=prayMatutinum`,
-# weekday's psalms was originally its next-door neighbor, once the
+# `version=Monastic Tridentinum 1617`) for both Wednesday and Thursday: the
-# psalms that moved out from between them are accounted for). None of the
+# real single-nocturn ferial office runs straight from the last psalm to
-# cross-psalm pairs split by the 2026-09-01 change carried a versicle of
+# the Capitulum, with no versicle anywhere in the psalmody — that embedded
-# their own, so no versicle needed repositioning.
+# line is inert in the source and was never actually emitted by the engine.
+# Removed; do not reintroduce it without a live query proving otherwise.
 #
 # Not live-verified against a running query (Monastic ferial ordinary time
 # isn't independently re-derivable that way once psalter-distribution.yml's
@@ -62,8 +64,8 @@
 
 monday:
   # All 9 psalms are Daym1_'s own (Monastic Matins Feria II) — no reslicing
-  # across weekday boundaries here, so both antiphon grouping and the
+  # across weekday boundaries here, so the antiphon grouping sits exactly
-  # versicle sit exactly where Daym1_ itself has them.
+  # where Daym1_ itself has it.
   groups:
     - psalms: [{ number: 32 }]
       antiphon:
@@ -83,9 +85,6 @@ monday:
       antiphon:
         la: "Revéla * Dómino viam meam."
         en: "Commit my way * to the Lord."
-      versicle:
-        v: { la: "Dómine, in cælo misericórdia tua.", en: "O Lord, thy mercy is in heaven," }
-        r: { la: "Et véritas tua usque ad nubes.", en: "And thy truth reacheth even to the clouds." }
     - psalms: [{ number: 37 }]
       antiphon:
         la: "Ne in ira tua * árguas me Dómine."
@@ -107,11 +106,7 @@ monday:
 
 tuesday:
   # 43-44 are Monday's own tail (Daym1_); 47-58 are Daym2_'s own opening (6
-  # of 9 psalms — the majority, hence Daym2_'s own versicle here); 59 is
+  # of 9 psalms — the majority); 59 is Wednesday's own opening (Daym3_).
-  # Wednesday's own opening (Daym3_). The versicle sits right after 49,
-  # exactly where Daym2_ itself has it (between the "49,51" and "52,53"
-  # groups — 51/52/53 all moved elsewhere in the reslice, but 49 and 54
-  # remain each other's nearest neighbor once they're gone).
   groups:
     - psalms: [{ number: 43 }]
       # New (2026-09-01): the source's shared antiphon for this pair
@@ -138,9 +133,6 @@ tuesday:
       antiphon:
         la: "Deus deórum * Dóminus locútus est."
         en: "The God of gods * the Lord hath spoken."
-      versicle:
-        v: { la: "Ímmola Deo sacrifícium laudis.", en: "Offer to God the sacrifice of praise." }
-        r: { la: "Et redde Altíssimo vota tua.", en: "And pay thy vows to the most High." }
     - psalms: [{ number: 54 }]
       antiphon:
         la: "Inténde in me * et exáudi me."
@@ -162,9 +154,7 @@ tuesday:
 
 wednesday:
   # 65-72 are Daym3_'s own (7 of 9 — the majority); 73 is Thursday's own
-  # opening (Daym4). The versicle sits between the "67ab" and "68ab"
+  # opening (Daym4).
-  # groups, exactly where Daym3_ itself has it — nothing moved out from
-  # between those two groups in the reslice, so the position is unchanged.
   groups:
     - psalms: [{ number: 65 }]
       antiphon:
@@ -174,9 +164,6 @@ wednesday:
       antiphon:
         la: "In ecclésiis, * benedícite Dóminum."
         en: "In the churches * bless ye the Lord."
-      versicle:
-        v: { la: "Benedícite, gentes, Deum nostrum.", en: "O bless our God, ye people." }
-        r: { la: "Et audítam fácite vocem laudis ejus.", en: "And make the voice of his praise to be heard." }
     - psalms: [{ number: 68, verses: "2-16" }, { number: 68, verses: "17-37" }]
       antiphon:
         la: "Quǽrite Dóminum * et vivet ánima vestra."
@@ -204,9 +191,7 @@ wednesday:
 
 thursday:
   # All 9 psalms are Daym4's own — no reslicing across weekday boundaries
-  # here either, so grouping and versicle position are both unchanged from
+  # here either, so the grouping is unchanged from the source.
-  # the source (the versicle sits between the "78" and "79,80" groups,
-  # exactly as Daym4 itself has it).
   groups:
     - psalms: [{ number: 76 }]
       antiphon:
@@ -220,9 +205,6 @@ thursday:
       antiphon:
         la: "Propítius esto * peccátis nostris, Dómine."
         en: "Forgive us our sins * O Lord."
-      versicle:
-        v: { la: "Deus, in sancto via tua.", en: "Thy way, O God, is in the holy place." }
-        r: { la: "Quis Deus magnus sicut Deus noster.", en: "Who is the great God like our God?" }
     - psalms: [{ number: 79 }]
       # New (2026-09-01): no real antiphon found elsewhere in the corpus
       # for Ps 79 alone; composed from its own opening verse (79:2).
@@ -254,10 +236,7 @@ friday:
   # elsewhere, so it's kept here on 93 alone; likewise 95's antiphon
   # originally also covered 96, which the redistribution's own documented
   # hand-adjustment moved to Saturday to keep both halves of Ps 103
-  # together there); 101-103 are Daym6_'s own opening (4 of 9). The
+  # together there); 101-103 are Daym6_'s own opening (4 of 9).
-  # versicle sits between the "93" and "95" groups, exactly where Daym5_
-  # itself has it (originally between "92/93" and "95/96" — 96 leaving for
-  # Saturday doesn't touch this boundary).
   groups:
     - psalms: [{ number: 85 }]
       antiphon:
@@ -271,9 +250,6 @@ friday:
       antiphon:
         la: "Exaltáre, * qui júdicas terram."
         en: "Lift up thyself, * thou that judgest the earth."
-      versicle:
-        v: { la: "Intret orátio mea in conspéctu tuo, Dómine.", en: "Let my prayer come before Thee, O Lord." }
-        r: { la: "Inclína aurem tuam ad precem meam.", en: "Incline Thine ear unto my cry." }
     - psalms: [{ number: 95 }]
       antiphon:
         la: "Cantáte Dómino, * et benedícite nómini ejus."
@@ -297,9 +273,7 @@ saturday:
   # Ps 96 is Daym5_'s own tail (moved here by the redistribution's own
   # documented hand-adjustment, swapped out of Friday to let both halves
   # of Ps 103 land there instead); 104-108 are Daym6_'s own tail (8 of 9 —
-  # the majority, hence Daym6_'s own versicle here). The versicle sits
+  # the majority).
-  # between the "104ab" and "105ab" groups, exactly where Daym6_ itself
-  # has it — nothing moved out from between those two groups.
   groups:
     - psalms: [{ number: 96 }]
       antiphon:
@@ -309,9 +283,6 @@ saturday:
       antiphon:
         la: "Lætétur cor * quæréntium Dóminum."
         en: "Let the heart of them rejoice, * that seek the Lord."
-      versicle:
-        v: { la: "Dómine, exáudi oratiónem meam.", en: "O Lord, hear my prayer." }
-        r: { la: "Et clamor meus ad te véniat.", en: "And let my cry come unto thee." }
     - psalms: [{ number: 105, verses: "1-31" }, { number: 105, verses: "32-48" }]
       antiphon:
         la: "Vísita nos, * Dómine, in salutári tuo."

src/hours/matins.ts

@@ -3,8 +3,8 @@
 // Builds its ordo programmatically per day rather than resolving a static
 // `data/hours/matins.yml` parts list the way every other hour does, because
 // the real shape (1 nocturn on a plain ferial day vs. 3 on a Sunday or a
-// Duplex+ feast, with a *variable* number of readings) doesn't fit that
+// Semiduplex+ feast, with a *variable* number of readings) doesn't fit
-// pattern.
+// that pattern.
 //
 // Critical framing (see memory `vu-not-a-reconstruction` / `vu-matins-
 // design`, and TODO.md's own Matins section): this is NOT a historical
@@ -76,7 +76,7 @@ import { getPsalmVerses } from '../psalter';
 import { getPsalmsFor, type PsalmRef } from '../psalter/distribution';
 import { getScriptureVerses } from '../scripture';
 import { getOpeningVersicleId } from './opening-versicle';
-import { isDoubleOrHigher, applyFlexaMark } from './antiphon';
+import { applyFlexaMark } from './antiphon';
 import {
   resolveCommon,
   getDayCollect,
@@ -208,7 +208,6 @@ function sundayNocturnFor(nocturnKey: 'nocturn1' | 'nocturn2' | 'nocturn3', day:
 interface FerialGroup {
   psalms: PsalmRef[];
   antiphon: BilingualText;
-  versicle?: { v: BilingualText; r: BilingualText };
 }
 interface FerialNocturn {
   groups: FerialGroup[];
@@ -434,12 +433,14 @@ function resolveMatinsHymn(day: LiturgicalDay): ResolvedText {
 
 /** The plain ferial weekday nocturn's real antiphoned psalmody (see
  * data/hours/matins-ferial-antiphons.yml's own header for how each
- * weekday's groups/versicle were reconciled against psalter-
+ * weekday's groups were reconciled against psalter-distribution.yml's own
- * distribution.yml's own "editorial redistribution" of the historical
+ * "editorial redistribution" of the historical per-weekday psalm set).
- * per-weekday psalm set). Every psalm-group carries its own antiphon
+ * Every psalm-group carries its own antiphon (incipit-or-full opening,
- * (incipit-or-full opening, same rank rule as Sunday's own nocturns), and
+ * same rank rule as Sunday's own nocturns). No versicle: an earlier
- * exactly one group per weekday carries a versicle+responsory, rendered
+ * version of this ported a mid-list V./R. line embedded in the source
- * as one combined V./R. block via `versicleText`. */
+ * `Psalmi matutinum.txt`, but that line is live-verified inert there — the
+ * real single-nocturn ferial office runs straight from the last psalm to
+ * the Capitulum (fixed 2026-09-02, see the data file's own header). */
 function ferialAntiphonedNocturn(day: LiturgicalDay): ResolvedPart[] {
   const nocturn = ferialAntiphons[day.weekday as Exclude<Weekday, 'sunday'>];
   const winner = resolveOfficeWinner(day);
@@ -459,22 +460,20 @@ function ferialAntiphonedNocturn(day: LiturgicalDay): ResolvedPart[] {
       });
     });
     parts.push({ kind: 'antiphon', text: full });
-    if (group.versicle) {
-      parts.push({ kind: 'versicle', text: versicleText(group.versicle) });
-    }
   }
   return parts;
 }
 
-/** Fallback for a Duplex+ weekday feast with no matins-psalmody-overrides
+/** Fallback for a Semiduplex+ weekday feast with no matins-psalmody-overrides
  * entry authored for its winner yet: the plain ferial weekday table,
  * chunked into 3 nocturns instead of 1. Bare (no antiphons, no canticles)
  * when `common` isn't given — genuinely nothing authored at all for this
  * winner, still used as-is for a duplex-majus+ winner with no Common
  * category either.
  *
- * When `common`/`commonId` *are* given (a duplex-rank winner whose Common
+ * When `common`/`commonId` *are* given (a Semiduplex- or Duplex-rank
- * category exists — user, 2026-08), each nocturn borrows that category's
+ * winner whose Common category exists — user, 2026-08, threshold lowered
+ * to Semiduplex 2026-09-02), each nocturn borrows that category's
  * own `nocturn{N}.versicle`: the ferial table only ever authors one
  * versicle for the whole (normally 1-nocturn) day, so a 3-nocturn split
  * leaves 2 of the 3 nocturns with none at all — Common's own 3 real
@@ -548,8 +547,8 @@ function withSingleAntiphon(refs: PsalmRef[], antiphonText: ResolvedText, winner
  * gathered for `day` — the office winner (if sanctoral), every
  * commemorated saint (a transferred-in feast already appears as `day.winner`
  * once `resolveDay` has applied the transfer, so it needs no separate
- * lookup here), and — only on a real 3-nocturn day (Sunday, or a Duplex+
+ * lookup here), and — only on a real 3-nocturn day (Sunday, or a
- * feast) — the plain temporal id itself (that Sunday's own Moralia-in-
+ * Semiduplex+ feast) — the plain temporal id itself (that Sunday's own Moralia-in-
  * Job-style commentary) plus, for dates from the 1st Sunday of August
  * through the eve of Advent, the calendar-month/week id (`month-week-<id>`,
  * calendar/month-week-id.ts's monthWeekId): the real historical Nocturn 2
@@ -735,12 +734,17 @@ export function resolveOrdo(date: string): ResolvedOrdo {
   const day = resolveDay(date);
   const winner = resolveOfficeWinner(day);
   const temporalId = resolveTemporalId(date);
-  // Every Sunday, unconditionally, or a Duplex+ sanctoral winner — the
+  // Every Sunday, unconditionally, or a Semiduplex+ sanctoral winner — the
-  // user's own chosen threshold (2026-08), not gated on whether any
+  // user's own chosen threshold (2026-08, lowered from Duplex to
-  // content is actually authored yet, same "eligible, not content-gated"
+  // Semiduplex 2026-09-02), not gated on whether any content is actually
-  // convention every other per-feast override in this app already uses
+  // authored yet, same "eligible, not content-gated" convention every
-  // (see hours/resolve-common.ts's getOfficeOverrideId).
+  // other per-feast override in this app already uses (see
-  const threeNocturns = day.weekday === 'sunday' || isDoubleOrHigher(winner);
+  // hours/resolve-common.ts's getOfficeOverrideId). Deliberately a
+  // separate check from `isDoubleOrHigher` (antiphon.ts) — that function
+  // drives the unrelated antiphon-doubling rule (full vs. incipit antiphon
+  // before the psalms) and stays floored at Duplex; the two thresholds
+  // only coincided before this change by accident, not by shared meaning.
+  const threeNocturns = day.weekday === 'sunday' || (winner.kind === 'sanctoral' && isAtLeast(winner.rank, 'semiduplex'));
   const pool = buildReadingPool(day, temporalId, date, threeNocturns);
   const [nocturn1Readings, nocturn2Readings, nocturn3Readings] = distributeIntoNocturns(pool, threeNocturns ? 3 : 1);
 
@@ -776,19 +780,21 @@ export function resolveOrdo(date: string): ResolvedOrdo {
     parts.push({ kind: 'te-deum', text: resolveCommon('te-deum') });
     parts.push({ kind: 'versicle', text: resolveCommon('te-decet-laus') });
   } else if (threeNocturns) {
-    // A Duplex+ weekday feast — genuinely different psalmody from a real
+    // A Semiduplex+ weekday feast — genuinely different psalmody from a
-    // Sunday's, not the same content reused.
+    // real Sunday's, not the same content reused.
     //   - Saint-specific proper: use its own full scheme, any rank.
     //   - No proper, rank duplex-majus+: Common's own full scheme (own
     //     psalm numbers, canticles) if authored; else the fully bare
     //     ferialPsalmodyThreeNocturns stand-in. Unaffected by the
-    //     duplex-and-below carve-out below (user, 2026-08).
+    //     below-duplex-majus carve-out below (user, 2026-08).
-    //   - No proper, rank exactly duplex (the floor of 3-nocturn
+    //   - No proper, rank Semiduplex or Duplex (below the floor of the
-    //     eligibility): ferial psalm numbers, not Common's own — but
+    //     duplex-majus+ tier, but at or above the floor of 3-nocturn
-    //     Common's per-nocturn versicle, and each nocturn's own Terce/
+    //     eligibility itself, lowered to Semiduplex 2026-09-02): ferial
-    //     Sext/None antiphon for that category, if authored (see
+    //     psalm numbers, not Common's own — but Common's per-nocturn
-    //     ferialPsalmodyThreeNocturns's own doc comment for why those
+    //     versicle, and each nocturn's own Terce/Sext/None antiphon for
-    //     three, not Common's own Matins Nocturn antiphons).
+    //     that category, if authored (see ferialPsalmodyThreeNocturns's
+    //     own doc comment for why those three, not Common's own Matins
+    //     Nocturn antiphons).
     const properOverride = winner.kind === 'sanctoral' ? getMatinsSaintOverride(winner.id) : undefined;
     const isAboveDuplex = winner.kind === 'sanctoral' && isAtLeast(winner.rank, 'duplex-majus');
     const commonOverride = winner.kind === 'sanctoral' && !properOverride ? getMatinsCommonOverride(winner.id) : undefined;

tests/hours/matins.test.ts

@@ -48,7 +48,7 @@ describe('resolveOrdo("matins", ...) ferial (1-nocturn) branch', () => {
     expect(ordo.parts.some((p) => p.kind === 'versicle' && p.text.text.la?.includes('Te decet laus'))).toBe(false);
   });
 
-  it("gives every nocturn psalm its own antiphon and includes Tuesday's own versicle (data/hours/matins-ferial-antiphons.yml)", () => {
+  it('gives every nocturn psalm its own antiphon and has no mid-nocturn versicle (data/hours/matins-ferial-antiphons.yml)', () => {
     // The nocturn's own psalms start at index 5 (after the two opening versicles/Ps3/heading/Ps94).
     const nocturnPsalms = ordo.parts.slice(5).filter((p) => p.kind === 'psalm') as {
       psalmNumber: number;
@@ -65,11 +65,11 @@ describe('resolveOrdo("matins", ...) ferial (1-nocturn) branch', () => {
         expect(p.antiphon.text.en).toBeTruthy();
       }
     }
+    // No versicle anywhere in the psalmody (fixed 2026-09-02) — the
+    // source's embedded mid-list V./R. line is live-verified inert; the
+    // real single-nocturn ferial office runs straight to the Capitulum.
     const nocturnVersicles = ordo.parts.slice(5).filter((p) => p.kind === 'versicle');
-    expect(nocturnVersicles).toHaveLength(1);
+    expect(nocturnVersicles).toHaveLength(0);
-    const versicleText = (nocturnVersicles[0] as { text: { text: Record<string, string> } }).text.text;
-    expect(versicleText.la).toContain('Ímmola Deo sacrifícium laudis');
-    expect(versicleText.la).toContain('Et redde Altíssimo vota tua');
   });
 
   it("resolves the user's own bible-plan readings for the day, not the historical lectionary", () => {
@@ -527,6 +527,49 @@ describe('resolveOrdo("matins", ...) Duplex+ weekday-feast (3-nocturn, non-Sunda
   });
 });
 
+describe('resolveOrdo("matins", ...) Semiduplex weekday-feast (3-nocturn threshold lowered 2026-09-02)', () => {
+  // St. Stephen of Hungary (Semiduplex, Common of a Confessor Not a
+  // Bishop, no proper Matins antiphon of his own) -- 2026-09-02, a
+  // Wednesday. Threshold was Duplex-or-higher before this fix, so a
+  // Semiduplex winner used to fall all the way through to the plain
+  // 1-nocturn ferial branch; the user's own design intent (2026-09-02) is
+  // that Semiduplex and Duplex share the same 3-nocturn/3-psalms-each
+  // shape, distinct from the 6/6/3-plus-canticles Sunday/Duplex-majus+
+  // scheme. Reuses the same already-working ferialPsalmodyThreeNocturns
+  // branch a plain-Duplex winner gets (see the describe block above) --
+  // no new content authoring was needed for this fix.
+  const ordo = resolveOrdo('matins', '2026-09-02');
+
+  it('splits the ferial 9-psalm pool into 3 nocturns of 3 each, plus a Te Deum, not the 1-nocturn ferial branch', () => {
+    const psalms = ordo.parts.filter((p) => p.kind === 'psalm').map((p) => (p as { psalmNumber: number }).psalmNumber);
+    expect(psalms).toEqual([3, 94, 65, 67, 67, 68, 68, 70, 71, 72, 73]);
+    expect(ordo.parts.some((p) => p.kind === 'te-deum')).toBe(true);
+    // No canticles -- reserved for Sunday/Duplex-majus+, not this tier.
+    expect(ordo.parts.some((p) => p.kind === 'canticle')).toBe(false);
+  });
+
+  it("uses Common-of-a-Confessor's own Terce/Sext/None antiphons and versicles, one distinct pair per nocturn", () => {
+    const psalmParts = ordo.parts.filter((p) => p.kind === 'psalm') as { psalmNumber: number; antiphon?: { text: Record<string, string>; status: Record<string, string> } }[];
+    const nocturnPsalms = psalmParts.filter((p) => ![3, 94].includes(p.psalmNumber));
+    expect(nocturnPsalms[0]?.antiphon?.text.la).toContain('Euge, serve bone');
+    expect(nocturnPsalms[3]?.antiphon?.text.la).toContain('Fidélis servus');
+    expect(nocturnPsalms[6]?.antiphon?.text.la).toContain('Serve bone');
+    for (const i of [0, 3, 6]) {
+      expect(nocturnPsalms[i]?.antiphon?.status.la).toBe('verified');
+      expect(nocturnPsalms[i]?.antiphon?.status.en).toBe('verified');
+    }
+    const versicles = ordo.parts.filter((p) => p.kind === 'versicle') as { text: { text: Record<string, string> } }[];
+    // The 3 nocturn-closing versicles (excluding the opening pair and the
+    // final Te decet laus) are Common-of-a-Confessor's own, one per
+    // nocturn -- not a stray mid-psalmody line.
+    const nocturnVersicles = versicles.slice(2, 5);
+    expect(nocturnVersicles).toHaveLength(3);
+    expect(nocturnVersicles[0]?.text.text.la).toContain('Amávit eum Dóminus');
+    expect(nocturnVersicles[1]?.text.text.la).toContain('Os justi meditábitur');
+    expect(nocturnVersicles[2]?.text.text.la).toContain('Lex Dei ejus in corde ipsíus');
+  });
+});
+
 describe('resolveOrdo("matins", ...) second Duplex+ weekday-feast proof — St. Andrew, Common of an Apostle', () => {
   // 2026-11-30 -- St. Andrew's own day outright ("S. Andreæ Apostoli",
   // not transferred that year: Nov 30 falls on a Monday, not a Sunday),