Add 4 more fixed Lord's/BVM feasts, and fix Our Lady of the Snows' Nocturn 3

Finding of the Holy Cross (May 3), the Transfiguration (Aug 6), the
Exaltation of the Holy Cross (Sep 14), and Dedication of the Basilica of
the Most Holy Savior (Nov 9, the Lateran) were all excluded under the
same stale "fixed feast of the Lord, not modeled" note that turned out
wrong for Our Lady of the Snows. All four have real, complete content in
the reference engine. Presentation of the BVM (Nov 21) was excluded
under the equivalent "fixed BVM feast" note and is added the same way.

- finding-of-the-holy-cross: fully proprium, own collect/antiphon/Matins
  throughout; now correctly outranks
  ss-alexander-eventius-theodulus-and-juvenal, matching what that
  saint's own file already documented as the live reality.
- transfiguration: same proprium shape. Its subordinate saints (Ss.
  Xystus/Felicissimus/Agapitus) stay excluded -- blocked by the real,
  separate octave/subordination-rendering gap, not by an unmodeled
  Transfiguration.
- exaltation-of-the-holy-cross: reuses the Finding of the Holy Cross's
  content wholesale (ex Sancti/05-03) -- collect/antiphon via a cross-id
  `propers` pointer, Matins nocturn-readings duplicated (no cross-id
  lookup exists for that mechanism).
- dedication-of-the-basilica-of-the-most-holy-savior: reuses the
  existing Common-of-a-Dedication (collect-c8, benedictus-antiphon-
  common-of-a-dedication), real unique Nocturn 2 vita of her own. Her
  secondary, St. Theodore, stays excluded for the same
  octave/subordination reason as above.
- presentation-of-the-bvm: real unique collect of her own; her
  Benedictus antiphon is a substituted Common reference
  (truncate-and-add-alleluia edit specific to this feast), authored as
  her own file.

Also: our-lady-of-the-snows.yml was missing its own Nocturn 3 (she
defers to Commune/C11's own Gospel-incipit-plus-Bede-homily, same as
Presentation of the BVM) -- added.

Test updates (not regressions): three tests had fixed proof dates
colliding with the newly-added feasts, updated to reflect the new,
correct behavior. npm test (365 tests) and tsc --noEmit both pass.

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

src/data/propers/common/finding-of-the-holy-cross-antiphon.yml

@@ -0,0 +1,12 @@
+# Read directly from web/www/horas/Latin/Sancti/05-03.txt's own [Ant 1]
+# and its English counterpart -- fully proper text, not a Common
+# template. Also used by exaltation-of-the-holy-cross.yml, which points
+# its own `propers` here directly rather than duplicating this file
+# (her `ex Sancti/05-03` Rule reuses this content wholesale).
+id: finding-of-the-holy-cross-antiphon
+text:
+  la: "O Crux, * splendídior cunctis astris, mundo célebris, homínibus multum amábilis, sánctior univérsis: quæ sola fuísti digna portáre taléntum mundi, dulce lignum, dulces clavos, dúlcia ferens póndera; salva præséntem catérvam in tuis hódie láudibus congregátam. (Allelúja, allelúja.)"
+  en: "O Cross, * surpassing all the stars in splendour, exceeding dear to all Christian people and world-renowned, holiest of earth's treasures: which only wast counted worthy to hold aloft the Price of our Redemption: sweet is thy wood and sweet thine iron, but sweetest of all the Burden that hung on thee! O that all who come this day to celebrate thy praises may find in thee salvation. (Alleluia, Alleluia.)"
+status:
+  la: verified
+  en: verified

src/data/propers/common/finding-of-the-holy-cross-collect.yml

@@ -0,0 +1,26 @@
+# Read directly from web/www/horas/Latin/Sancti/05-03.txt's own
+# [Oratio] and its English counterpart -- fully proper text, not a
+# Common template. Also used by exaltation-of-the-holy-cross.yml, which
+# points its own `propers` here directly rather than duplicating this
+# file (her `ex Sancti/05-03` Rule reuses this content wholesale).
+id: finding-of-the-holy-cross-collect
+text:
+  la: |
+    Orémus.
+    Deus, qui in præclára salutíferæ Crucis Inventióne, passiónis tuæ mirácula suscitásti:
+    concéde; ut vitális ligni prétio, ætérnæ vitæ suffrágia consequámur:
+    Qui vivis et regnas cum Deo Patre, in unitáte Spíritus Sancti, Deus, per ómnia sǽcula
+    sæculórum.
+    ℟. Amen.
+  en: |
+    Let us pray.
+    O God, Who didst cause that the Cross of our salvation should in most honourable wise be
+    found again, and Who didst manifest thereby the marvellous efficacy of thy sufferings,
+    mercifully grant that by the Ransom which Thou didst pay upon that tree of life we may
+    finally attain unto life eternal.
+    Who livest and reignest with God the Father, in the unity of the Holy Ghost, God, world
+    without end.
+    ℟. Amen.
+status:
+  la: verified
+  en: verified

src/data/propers/common/presentation-of-the-bvm-antiphon.yml

@@ -0,0 +1,18 @@
+# Read directly from web/www/horas/Latin/Sancti/11-21.txt's own [Ant 1]
+# cross-reference and its English counterpart -- `@Commune/C10:Ant 2_`
+# (Common of the BVM on Saturday) with a feast-specific substitution
+# applied and computed by hand here: `s/Christo:.*/Christo, allelúja./`
+# (Latin) / `s/Christ;.*/Christ, alleluia./` (English) -- truncates the
+# Common's own antiphon after "...Jesu Christo"/"...Jesus Christ" and
+# appends ", allelúja."/", alleluia." instead of continuing with "ora
+# pro pópulo..."/"pray for the people...". Effectively proper to this
+# feast (the substitution isn't shared by any other saint using C10),
+# so authored as its own file via `propers` rather than as a reusable
+# Common template.
+id: presentation-of-the-bvm-antiphon
+text:
+  la: "Beáta Dei Génetrix, María, * Virgo perpétua, templum Dómini, sacrárium Spíritus Sancti, sola sine exémplo placuísti Dómino nostro Jesu Christo, allelúja."
+  en: "O Blessed Mary, * Mother of God, Virgin for ever, temple of the Lord, sanctuary of the Holy Ghost, thou, without any example before thee, didst make thyself well-pleasing in the sight of our Lord Jesus Christ, alleluia."
+status:
+  la: verified
+  en: verified

src/data/propers/common/presentation-of-the-bvm-collect.yml

@@ -0,0 +1,25 @@
+# Read directly from web/www/horas/Latin/Sancti/11-21.txt's own [Oratio]
+# and its English counterpart -- a real, proper collect, not a Common
+# fallback (unlike this feast's Benedictus antiphon).
+id: presentation-of-the-bvm-collect
+text:
+  la: |
+    Orémus.
+    Deus, qui beátam Maríam semper Vírginem, Spíritus Sancti habitáculum, hodiérna die in
+    templo præsentári voluísti: præsta, quǽsumus; ut, ejus intercessióne, in templo glóriæ
+    tuæ præsentári mereámur.
+    Per eúndem 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 wast pleased that the blessed Mary always a Virgin, being herself the
+    dwelling-place of the Holy Ghost, should, as on this day, be presented in thine earthly
+    Temple, grant, we beseech thee, that by her prayers we may worthily be presented in the
+    heavenly Temple of thy glory.
+    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.
+    ℟. Amen.
+status:
+  la: verified
+  en: verified

src/data/propers/common/transfiguration-antiphon.yml

@@ -0,0 +1,10 @@
+# Read directly from web/www/horas/Latin/Sancti/08-06.txt's own [Ant 1]
+# and its English counterpart -- fully proper text, not a Common
+# template.
+id: transfiguration-antiphon
+text:
+  la: "Christus Jesus, * splendor Patris et figúra substántiæ ejus, portans ómnia verbo virtútis suæ, purgatiónem peccatórum fáciens, in monte excélso gloriósus apparére hódie dignátus est."
+  en: "Christ Jesus, being the Brightness * of the Father's glory, and the express Image of His Person, and upholding all things by the word of His power, when He was about purging our sins, was pleased, as on this day, to manifest forth His glory upon an high mountain."
+status:
+  la: verified
+  en: verified

src/data/propers/common/transfiguration-collect.yml

@@ -0,0 +1,26 @@
+# Read directly from web/www/horas/Latin/Sancti/08-06.txt's own
+# [Oratio] and its English counterpart -- fully proper text, not a
+# Common template.
+id: transfiguration-collect
+text:
+  la: |
+    Orémus.
+    Deus, qui fídei sacraménta in Unigéniti tui gloriósa Transfiguratióne patrum testimónio
+    roborásti, et adoptiónem filiórum perféctam, voce delápsa in nube lúcida, mirabíliter
+    præsignásti: concéde propítius; ut ipsíus Regis glóriæ nos coherédes effícias, et
+    ejúsdem glóriæ tríbuas esse consórtes.
+    Qui vivis et regnas cum Deo Patre, in unitáte Spíritus Sancti, Deus, per ómnia sǽcula
+    sæculórum.
+    ℟. Amen.
+  en: |
+    Let us pray.
+    O God, Who, in the glorious Transfiguration of thine Only Begotten Son didst attest the
+    mysteries of the Faith by the witness of the Fathers, and didst wonderfully signify by a
+    voice out of a bright cloud, the adoption of sons, mercifully grant unto us to be made
+    co-heirs with the very King of glory, and bestow upon us a partaking of His glory.
+    Who liveth and reigneth with God the Father, in the unity of the Holy Ghost, God, world
+    without end.
+    ℟. Amen.
+status:
+  la: verified
+  en: verified