Add December Matins readings for SanctiM-track saints, completing the pass

13 of December's 15 SanctiM-track saints authored (st-bibiana, st-nicholas,
st-ambrose, immaculate-conception, st-damasus, st-lucy, st-thomas-apostle,
st-stephen-protomartyr, st-john-apostle, holy-innocents, st-thomas-becket,
st-silvester-i, st-eusebius-of-vercelli); st-barbara and st-melchiades left
unauthored as Common-only. This is the twelfth and final month of the
SanctiM (Monastic 1617)-track saints' Matins readings pass — 129 saints
authored across the whole year.

Adding St. Eusebius of Vercelli's content surfaces a 3rd Matins lesson on
the existing Advent III Tuesday proof date (Dec 15 falls under his
commemoration); updated matins.test.ts accordingly — the "commemorations
get their own reading" design working as intended, not a regression.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/data/propers/nocturn-readings/st-ambrose.yml

@@ -0,0 +1,93 @@
+# Matins Nocturn 2 reading for St. Ambrose, Bishop, Confessor, Doctor
+# of the Church (Dec 7) — SanctiM/12-07.txt inherits the whole day
+# (`@Sancti/12-07`) with no Nocturn 2 override, so this feast's own
+# proper content is sourced from the Tridentine track exactly as for a
+# pre-1955 saint (see memory vu-matins-pre1955-saints,
+# vu-matins-sanctim-saints).
+# web/www/horas/Latin/Sancti/12-07.txt, English/Sancti/12-07.txt.
+# Lectio4-6 combined into one reading, one continuous vita, no
+# genuine source break.
+id: st-ambrose
+readings:
+  - nocturn: 2
+    isGospel: false
+    text:
+      la: >-
+        Ambrósius epíscopus Mediolanénsis, Ambrósii civis Románi fílius, patre Gálliæ
+        præfécto natus est. In hujus infántis ore exámen apum consedísse dícitur: quæ res
+        divínam viri eloquéntiam præmonstrábat. Romæ liberálibus disciplínis erudítus est.
+        Post a Probo præfécto Ligúriæ et Æmíliæ præpósitus: unde póstea, ejúsdem Probi jussu,
+        cum potestáte Mediolánum venit; ubi, mórtuo Auxéntio Ariáno epíscopo, pópulus de
+        successóre deligéndo dissidébat. Quare Ambrósius, pro offícii sui múnere ecclésiam
+        ingréssus, ut commótam seditiónem sedáret, cum multa de quiéte et tranquillitáte
+        reipúblicæ præcláre dixísset, derepénte púero Ambrósium epíscopum exclamánte,
+        univérsi pópuli vox erúpit, Ambrósium epíscopum deposcéntis.
+
+
+        Recusánte illo et eórum précibus resisténte, ardens pópuli stúdium ad Valentiniánum
+        imperatórem delátum est; cui gratíssimum fuit, a se deléctos júdices ad sacerdótium
+        postulári. Fuit id étiam Probo præfécto jucúndum, qui Ambrósio proficiscénti quasi
+        divínans díxerat: Vade, age, non ut judex, sed ut epíscopus. Itaque cum ad pópuli
+        desidérium imperatóris volúntas accéderet, Ambrósius baptizátus (erat enim
+        catechúmenus) sacrísque initiátus, ac servátis ómnibus ex institúto Ecclésiæ órdinum
+        grádibus, octávo die, qui fuit séptimo Idus Decémbris, episcopále onus suscépit.
+        Factus epíscopus, cathólicam fidem et disciplínam ecclesiásticam acérrime deféndit;
+        multósque Ariános, et álios hæréticos ad fídei veritátem convértit, in quibus
+        claríssimum Ecclésiæ lumen sanctum Augustínum Jesu Christo péperit.
+
+
+        Gratiáno imperatóre occíso, ad Máximum ejus interfectórem legátus íterum proféctus
+        est; eóque pœniténtiam ágere recusánte, se ab ejus communióne semóvit. Theodósium
+        imperatórem, propter cædem Thessalonícæ factam, ingréssu ecclésiæ prohíbuit. Cui, cum
+        ille David quoque regem adúlterum et homicídam fuísse dixísset, respóndit Ambrósius:
+        Qui secútus es errántem, séquere pœniténtem. Quare Theodósius sibi ab eo impósitam
+        públicam pœniténtiam humíliter egit. Ergo sanctus epíscopus pro Ecclésia Dei máximis
+        labóribus curísque perfúnctus, multis libris étiam egrégie conscrípsit, ántequam in
+        morbum incíderet, mortis suæ diem prædíxit. Ad quem ægrótum Honorátus Vercellénsis
+        epíscopus, Dei voce ter admónitus, accúrrit, eíque sanctum Dómini corpus prǽbuit: quo
+        ille sumpto, conformátis in crucis similitúdinem mánibus, orans, ánimam Deo réddidit
+        prídie Nonas Aprílis, anno post Christum natum trecentésimo nonagésimo séptimo.
+      en: >-
+        Ambrose, Bishop of Milan, was the son of another Ambrose, a Roman citizen, and was
+        born when his father was Prefect of Gaul. A swarm of bees settled upon his face when
+        he was in his cradle, which was considered an omen of his future eloquence. He
+        received a liberal education at Rome. He was afterwards, under the Prefect Probus,
+        made governor of Liguria and Emilia, and so came with authority to Milan. Auxentius, an
+        Arian, who had been intruded into the Bishopric of Milan, happening to die, the most
+        violent disputes arose about the choice of a successor. Ambrose came to the church in
+        his official capacity, and urged upon the contending factions, in a long and powerful
+        speech, the necessity of keeping the public peace; whereupon a child suddenly cried
+        out, Ambrose, Bishop, and the whole assembly took it up, and unanimously called for his
+        election.
+
+
+        Ambrose refused, and would not yield to their prayers, whereupon they carried their
+        petition to the Emperor Valentinian. It was very pleasing to this Prince that those he
+        had appointed as judges should be chosen Bishops, as also to the Prefect Probus, who
+        had, as it were prophetically, said to him when he appointed him, Go and govern them
+        more like a Bishop than a Judge. When the will of the Emperor was added to the desire
+        of the people, Ambrose yielded, and received Baptism, (for hitherto he was only a
+        Catechumen,) Confirmation, and Communion, and then the several Orders on successive
+        days, till on the eighth day, which was the 7th of December, the weight of the
+        Episcopate was laid upon his shoulders. Being made Bishop, he showed himself a stout
+        upholder of the Catholic faith, and the discipline of the Church, and turned to the
+        truth great numbers of Arians and other heretics, and, among them, he begat in Christ
+        Jesus that burning and shining light of the Church, Augustine.
+
+
+        After the murder of the Emperor Gratian, Ambrose was sent as an ambassador to Maximus,
+        by whom he had been slain, and, as he refused to repent, the Bishop renounced his
+        communion. After the massacre which the Emperor Theodosius had commanded at
+        Thessalonica, he refused to permit that Prince to enter a church. The Emperor pleaded
+        that he was no worse than David, who had been guilty of adultery and murder, to which
+        Ambrose answered him, As thou hast followed him in his sin, follow him also in his
+        repentance. Then Theodosius humbly did public penance laid upon him by the Bishop. At
+        length the Saint was worn out with his continual labour and care for the Church, (for
+        the which also he composed many excellent books,) and foretold that the day of his
+        death was at hand, though he had not then fallen into his last sickness. As he lay
+        dying, Honoratus, Bishop of Vercelli, heard a voice from God three times crying to him
+        that the hour of Ambrose's departure was come, whereupon he went to him quickly, and
+        gave him the sacred Body of our Lord. When he had received It, the Saint, still
+        praying, with his hands stretched out in the form of a cross, gave his spirit to God,
+        upon the 4th day of April, in the year of Christ, 397.
+    status: { la: verified, en: verified }