propers: add May's collect and antiphon text

Real collect text for all 13 May saints that have one, plus a real
antiphon for the 3 that have one of their own (Ss. Philip and James, St.
John Before the Latin Gate, the Apparition of St. Michael) — same
extraction method as prior months. Two saints (St. Peter Celestine, St.
Urban I) have an [Ant 1] in the source that turned out to just be a
cross-reference to the generic Common template, not real unique text, so
no antiphon file was authored for them.

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

src/data/propers/common/st-ubald-collect.yml

@@ -0,0 +1,18 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617) — read
+# directly from the reference engine's own real-date output (2029-05-16).
+# Same convention as data/propers/temporal/*-collect.yml.
+id: st-ubald-collect
+text:
+  la: |
+    Orémus.
+    Auxílium tuum nobis, Dómine, quǽsumus, placátus impénde: et, intercessióne beáti Ubáldi Confessóris tui atque Pontíficis, contra omnes diáboli nequítias déxteram super nos tuæ propitiatiónis exténde.
+    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.
+    Graciously help us, we beseech thee, O Lord, and at the petition of thy blessed Confessor and Bishop Ubald, stretch forth the right hand of thy mercy to shield us against all the fiery darts of the wicked one.
+    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