Add May sanctoral content: 10 saints plus the Queenship of the BVM

Continues the full-year sanctoral import (see TODO.md/memory for Jan-Apr):
St. Pius V, St. Antoninus, St. Robert Bellarmine, St. John Baptist de la
Salle, St. Paschal Baylon, St. Venantius, St. Bernardine of Siena, St. John
Baptist de Rossi, St. Augustine of Canterbury, St. Mary Magdalene de Pazzi,
and the Queenship of the BVM (May 31, Duplex II Classis, instituted by Pius
XII's 1954 "Ad cæli Reginam" — full proper content, not a Common fallback).

Adding the Queenship to May 31 surfaces a real collision with Trinity
Sunday in years where Trinity falls on May 31 (2026): since this app
models Trinitytide Sundays as plain ordinary-sunday with no special
first-class standing, a Duplex+ sanctoral feast wins outright there per
the existing precedence rule. Updated the two tests pinned to that date
accordingly, with a third moved to a Trinity Sunday date (2023-06-04)
free of any sanctoral entry to keep testing the octave-vs-anchor-day
interaction in isolation.

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

src/data/propers/common/st-augustine-of-canterbury-collect.yml

@@ -0,0 +1,25 @@
+# Read directly from web/www/horas/Latin/Sancti/05-28.txt's own
+# [Oratio] and its English counterpart.
+id: st-augustine-of-canterbury-collect
+text:
+  la: |
+    Orémus.
+    Deus, qui Anglórum gentes, prædicatióne et miráculis beáti Augustíni Confessóris tui
+    atque Pontíficis, veræ fídei luce illustráre dignátus es: concéde; ut, ipso
+    interveniénte, errántium corda ad veritátis tuæ rédeant unitátem, et nos in tua
+    simus voluntáte concórdes.
+    Per Dóminum nostrum Jesum Christum, Fílium tuum: qui tecum vivit et regnat in unitáte
+    Spíritus Sancti, Deus, per ómnia sǽcula sæculórum.
+    ℟. Amen.
+  en: |
+    Let us pray.
+    O God, Who graciously enlightened the English peoples with the light of the true
+    faith by the preaching and miracles of blessed Augustine, thy Confessor and Bishop,
+    grant, through his intercession, that the hearts of those who have strayed may
+    return to the unity of the true faith and that we may be in harmony with thy will.
+    Through Jesus Christ, thy Son our Lord, Who liveth and reigneth with thee, in the
+    unity of the Holy Ghost, God, world without end.
+    ℟. Amen.
+status:
+  la: verified
+  en: verified