Build the Paschaltide "Suffragium Paschale" mechanism

Throughout Paschaltide (Eastertide/Ascensiontide/Pentecost), two
things happen wherever they'd otherwise show: the ordinary
5-suffrage set (Cross/BVM/Joseph/Apostles/Peace) collapses into one
alleluia-form "Suffragium Paschale" (Lauds and Vespers each have
their own distinct antiphon here, unlike the ordinary suffrages,
which share identical text at both hours), and the ferial-Preces
litany drops entirely rather than being replaced. Live-verified
against the reference source's own [Suffragium] macro directly,
byte-identical between Monastic Tridentinum 1617 and Tridentine 1906.

Exported isPaschaltide(season) from resolve-common.ts (wraps the
pre-existing PASCHALTIDE_SEASONS set). resolveSuffrages gained a
third hourId parameter to pick the right antiphon; the Preces
omission is a small new check gated on the same isFerialOrVigil
predicate that already selects the ferial litany form.

Authored lauds-suffrage-paschale.yml and vespers-suffrage-
paschale.yml -- English on the Vespers antiphon is this project's own
translation (the reference engine leaves it untranslated) and marked
draft; everything else verified.

Closes the last item in TODO.md's "Mechanism gaps" priority tier.

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

src/data/propers/common/lauds-suffrage-paschale.yml

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+# Throughout Paschaltide (Eastertide/Ascensiontide/Pentecost), the whole
+# ordinary 5-suffrage set (Cross/BVM/Joseph/Apostles/Peace) collapses into
+# this single alleluia-form "Suffragium Paschale" instead — live-verified
+# against Divinum Officium (Monastic Tridentinum 1617 and Tridentine 1906,
+# byte-identical between the two tracks), Lauds live query, 2026-04-20 (a
+# plain Eastertide feria). Distinct antiphon from Vespers' own
+# (vespers-suffrage-paschale.yml, "Crucem sanctam súbiit..."); the
+# versicle/response and collect are shared between both hours.
+id: lauds-suffrage-paschale
+text:
+  la: |
+    Ant. Crucifíxus surréxit a mórtuis, et redémit nos, allelúja, allelúja.
+    V. Dícite in natiónibus, allelúja.
+    R. Quia Dóminus regnávit a ligno, allelúja.
+    Orémus.
+    Deus qui pro nobis Fílium tuum Crucis patíbulum subíre voluísti, ut inimíci a nobis expélleres potestátem: concéde nobis fámulis tuis; ut resurrectiónis grátiam consequámur.
+    Per eúmdem Dóminum nostrum Jesum Christum Fílium tuum, qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus, per ómnia sǽcula sæculórum.
+    R. Amen.
+  en: |
+    Ant. He that was crucified is risen from the dead, and hath redeemed us. Alleluia, alleluia.
+    V. Say among the heathen, alleluia.
+    R. That the Lord reigneth from the tree, alleluia.
+    Let us pray.
+    O God, who didst send thy Son to suffer death for us upon the Cross, that thou mightest deliver us from the power of the enemy: grant unto us thy servants to be made partakers of his Resurrection.
+    Through the same Jesus Christ, thy Son, Our Lord, Who liveth and reigneth with thee in the unity of the Holy Ghost, God, world without end.
+    R. Amen.
+status:
+  la: verified
+  en: verified

src/data/propers/common/vespers-suffrage-paschale.yml

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+# Vespers' own antiphon for the same "Suffragium Paschale" substitution
+# described in lauds-suffrage-paschale.yml's own header — shares that
+# file's versicle/response and collect, but its own distinct antiphon
+# ("Crucem sanctam súbiit..."), live-verified against Divinum Officium
+# (Monastic Tridentinum 1617), Vespers live query, 2026-04-20 (a plain
+# Eastertide feria). English antiphon translation is this project's own
+# (the reference engine's own English-language render leaves this
+# particular antiphon untranslated, Latin-only) — status left `draft`
+# for the English text specifically pending a better-sourced translation.
+id: vespers-suffrage-paschale
+text:
+  la: |
+    Ant. Crucem sanctam súbiit, qui inférnum confrégit; accínctus est poténtia, surréxit die tértia, allelúja.
+    V. Dícite in natiónibus, allelúja.
+    R. Quia Dóminus regnávit a ligno, allelúja.
+    Orémus.
+    Deus qui pro nobis Fílium tuum Crucis patíbulum subíre voluísti, ut inimíci a nobis expélleres potestátem: concéde nobis fámulis tuis; ut resurrectiónis grátiam consequámur.
+    Per eúmdem Dóminum nostrum Jesum Christum Fílium tuum, qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus, per ómnia sǽcula sæculórum.
+    R. Amen.
+  en: |
+    Ant. He bore the holy Cross, who broke the gates of hell; he was girded with power, and rose again on the third day, alleluia.
+    V. Say among the heathen, alleluia.
+    R. That the Lord reigneth from the tree, alleluia.
+    Let us pray.
+    O God, who didst send thy Son to suffer death for us upon the Cross, that thou mightest deliver us from the power of the enemy: grant unto us thy servants to be made partakers of his Resurrection.
+    Through the same Jesus Christ, thy Son, Our Lord, Who liveth and reigneth with thee in the unity of the Holy Ghost, God, world without end.
+    R. Amen.
+status:
+  la: verified
+  en: draft