calendar: pull December's sanctoral calendar (pre-1955 pull, 12/12 -- complete)

16 saints, plus a propers-slug update for the pre-existing Immaculate
Conception entry. Also extends the Advent temporal-category fix
(previous commit) to Christmastide: St. Thomas of Canterbury, only
Semiduplex, wins outright within the Christmas Octave in the real
Monastic 1617 engine, which the stronger privileged-feria tier would
have wrongly forbidden -- Christmastide now shares Advent's
privileged-feria-minor tier instead. Every real winner this month falls
within one of these two newly-corrected seasons.

This completes the first pass of the pre-1955 sanctoral calendar pull
across all twelve months.

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

src/data/calendar/saints/holy-innocents.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2026-12-28) -- wins outright, Duplex II. classis, within
+# Christmas's Octave (privileged-feria-minor), Octave day commemorated in
+# return. About the Innocents slain at Christ's birth, not a feast of the
+# Lord/BVM directly, so kept in scope like every other real saint's day
+# this pull has found. Own proper collect and antiphon.
+id: holy-innocents
+name: "The Holy Innocents, Martyrs"
+rank: duplex-2-classis
+common: common-of-several-martyrs
+propers: "holy-innocents"

src/data/calendar/saints/immaculate-conception.yml

@@ -1,7 +1,9 @@
 # Verified against Divinum Officium (web/www/horas/Latin/Sancti/12-08.txt,
-# untagged/default [Rank] block).
+# untagged/default [Rank] block). Propers backfilled during the December
+# pull now that the collect-pulling methodology exists -- own proper
+# collect and antiphon.
 id: immaculate-conception
 name: "The Immaculate Conception of the Blessed Virgin Mary"
 rank: duplex-1-classis
 common: common-of-the-bvm
-propers: null
+propers: "immaculate-conception"

src/data/calendar/saints/st-ambrose.yml

@@ -0,0 +1,12 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2026-12-07) -- an ordinary Advent feria
+# (privileged-feria-minor), Duplex easily wins outright, feria
+# commemorated in return. No unique collect: the raw file's own [Rule] is
+# a plain cross-reference to a generic Common formula ("vide C4a"), not
+# unique text -- genuinely his own file, just entirely Common-based, not
+# a naming mismatch this time.
+id: st-ambrose
+name: "St. Ambrose, Bishop, Confessor and Doctor of the Church"
+rank: duplex
+common: common-of-a-confessor-bishop
+propers: null

src/data/calendar/saints/st-barbara.yml

@@ -0,0 +1,13 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-04) -- an ordinary Advent feria
+# (privileged-feria-minor), so this Simplex saint is only ever
+# commemorated here, the feria staying primary. No unique collect: the
+# raw file at this MM-DD slot (Sancti/12-04.txt) is actually St. Peter
+# Chrysologus's (a later Doctor-of-the-Church addition to this filename
+# slot) -- a live prayTertia query for the Monastic 1617 track returns no
+# Oratio at all, confirming propers: null is correct.
+id: st-barbara
+name: "St. Barbara, Virgin and Martyr"
+rank: simplex
+common: common-of-a-virgin-martyr
+propers: null

src/data/calendar/saints/st-bibiana.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-02) -- an ordinary (non-Ember) Advent feria
+# (privileged-feria-minor, see calendar/types.ts), so this Simplex saint
+# is only ever commemorated here, the feria itself staying primary; the
+# concrete case that led to this month's temporal-category fix. Own
+# proper collect, no unique antiphon of her own.
+id: st-bibiana
+name: "St. Bibiana, Virgin and Martyr"
+rank: simplex
+common: common-of-a-virgin-martyr
+propers: "st-bibiana"

src/data/calendar/saints/st-damasus.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-11) -- an ordinary Advent feria
+# (privileged-feria-minor), Semiduplex wins outright, feria commemorated
+# in return. Own proper collect (Latin only -- see
+# propers/common/st-damasus-collect.yml for the missing-English note), no
+# unique antiphon of his own.
+id: st-damasus
+name: "St. Damasus I, Pope and Confessor"
+rank: semiduplex
+common: common-of-a-confessor-bishop
+propers: "st-damasus"

src/data/calendar/saints/st-eusebius-of-vercelli.yml

@@ -0,0 +1,16 @@
+# A monastic-calendar-specific placement: the base Tridentine table
+# (1570.txt) doesn't have this saint at all; the monastic-specific delta
+# table (M1617.txt) places him here via a same-day redirect notation
+# ("12-15=12-16=..."). Verified live (Monastic Tridentinum 1617,
+# 2025-12-15) -- an ordinary Advent feria (privileged-feria-minor),
+# Semiduplex wins outright, feria commemorated in return. No unique
+# collect: the raw file actually found at this MM-DD slot
+# (Sancti/12-15.txt) is the later (post-1854) Octave of the Immaculate
+# Conception's, not this saint's at all -- a live prayTertia query for
+# the Monastic 1617 track returns no Oratio, confirming propers: null is
+# correct.
+id: st-eusebius-of-vercelli
+name: "St. Eusebius of Vercelli, Bishop and Martyr"
+rank: semiduplex
+common: common-of-a-martyr-bishop
+propers: null

src/data/calendar/saints/st-john-apostle.yml

@@ -0,0 +1,9 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-27) -- wins outright, Duplex II. classis, within
+# Christmas's Octave (privileged-feria-minor), Octave day commemorated in
+# return. Own proper collect and antiphon.
+id: st-john-apostle
+name: "St. John, Apostle and Evangelist"
+rank: duplex-2-classis
+common: common-of-an-evangelist
+propers: "st-john-apostle"

src/data/calendar/saints/st-lucy.yml

@@ -0,0 +1,12 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-13) -- an ordinary Advent feria
+# (privileged-feria-minor), Duplex wins outright, feria commemorated in
+# return. Own proper antiphon; its own [Oratio] is a plain cross-
+# reference to a generic Common formula (@Commune/C7a), not unique text,
+# so getDayCollect resolves honestly missing for her despite propers
+# being set -- same pattern as February's St. Agatha.
+id: st-lucy
+name: "St. Lucy, Virgin and Martyr"
+rank: duplex
+common: common-of-a-virgin-martyr
+propers: "st-lucy"

src/data/calendar/saints/st-melchiades.yml

@@ -0,0 +1,10 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-10) -- an ordinary Advent feria
+# (privileged-feria-minor), so this Simplex saint is only ever
+# commemorated here, the feria staying primary. No unique collect: no raw
+# file exists at all at this MM-DD slot (Sancti/12-10.txt).
+id: st-melchiades
+name: "St. Melchiades, Pope and Martyr"
+rank: simplex
+common: common-of-a-martyr-bishop
+propers: null

src/data/calendar/saints/st-nicholas.yml

@@ -0,0 +1,12 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-06) -- an ordinary Advent feria
+# (privileged-feria-minor); Semiduplex is enough to win outright here
+# (unlike the stricter privileged-feria/Ember tier), with the feria
+# itself commemorated in return -- the concrete case that revealed this
+# month's temporal-category fix. Own proper collect, no unique antiphon
+# of his own.
+id: st-nicholas
+name: "St. Nicholas, Bishop and Confessor"
+rank: semiduplex
+common: common-of-a-confessor-bishop
+propers: "st-nicholas"

src/data/calendar/saints/st-sabbas.yml

@@ -0,0 +1,10 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-05) -- an ordinary Advent feria
+# (privileged-feria-minor), so this Simplex saint is only ever
+# commemorated here, the feria staying primary. No unique collect: the
+# raw file at this MM-DD slot (Sancti/12-05.txt) is empty.
+id: st-sabbas
+name: "St. Sabbas, Abbot"
+rank: simplex
+common: common-of-an-abbot
+propers: null

src/data/calendar/saints/st-silvester-i.yml

@@ -0,0 +1,12 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-31) -- wins outright, Duplex, within Christmas's
+# Octave (privileged-feria-minor), Octave day commemorated in return.
+# Distinct from November's St. Silvester, Abbot (st-silvester-abbot.yml,
+# Sylvester Gozzolini) -- this is Pope St. Sylvester I. No unique collect:
+# the raw file's own [Oratio] is a plain cross-reference to a generic
+# Common formula (@Commune/C4), not unique text.
+id: st-silvester-i
+name: "St. Silvester I, Pope and Confessor"
+rank: duplex
+common: common-of-a-confessor-bishop
+propers: null

src/data/calendar/saints/st-stephen-protomartyr.yml

@@ -0,0 +1,12 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-26) -- wins outright, Duplex II. classis, within
+# Christmas's own Octave (privileged-feria-minor, see this month's
+# temporal-category fix), with the Octave day itself commemorated in
+# return. Own proper collect and antiphon -- his Dec 26 own feast, the
+# canonical source August's finding-of-st-stephen.yml and this pull's
+# other Stephen-related feasts cross-reference or duplicate from.
+id: st-stephen-protomartyr
+name: "St. Stephen, Protomartyr"
+rank: duplex-2-classis
+common: common-of-a-martyr
+propers: "st-stephen-protomartyr"

src/data/calendar/saints/st-thomas-apostle.yml

@@ -0,0 +1,9 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2026-12-21) -- an ordinary Advent feria
+# (privileged-feria-minor), Duplex II. classis wins outright easily, feria
+# commemorated in return. Own proper collect and antiphon.
+id: st-thomas-apostle
+name: "St. Thomas, Apostle"
+rank: duplex-2-classis
+common: common-of-an-apostle
+propers: "st-thomas-apostle"

src/data/calendar/saints/st-thomas-becket.yml

@@ -0,0 +1,13 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-12-29) -- wins outright, Semiduplex, within
+# Christmas's Octave (privileged-feria-minor) -- the concrete case that
+# revealed this month's temporal-category fix (Semiduplex, not just
+# Duplex+, wins outright here, which the original single-tier
+# `privileged-feria` model would have wrongly forbidden). Octave day
+# commemorated in return. Own proper collect, no unique antiphon of his
+# own.
+id: st-thomas-becket
+name: "St. Thomas of Canterbury, Bishop and Martyr"
+rank: semiduplex
+common: common-of-a-martyr-bishop
+propers: "st-thomas-becket"

src/data/calendar/saints/vigil-of-st-thomas.yml

@@ -0,0 +1,15 @@
+# A real vigil, landing on Advent's Ember Saturday every year (Dec 20 is
+# fixed, and Advent Ember Saturday is defined relative to it -- see the
+# raw table's own "(in missa tantum)" tag, meaning the *real* engine
+# commemorates this vigil at Mass only, keeping Ember Saturday
+# (privileged-feria, see calendar/types.ts) as the Office's primary. This
+# app doesn't model the Mass-vs-Office distinction anywhere (same known
+# simplification as September's Vigil of St. Matthew), so here it simply
+# follows the ordinary privileged-feria/vigil transfer rule instead. No
+# unique collect: the raw file at this MM-DD slot (Sancti/12-20.txt) is
+# empty.
+id: vigil-of-st-thomas
+name: "Vigil of St. Thomas"
+rank: vigil
+common: common-of-a-vigil
+propers: null

src/data/calendar/sanctoral-calendar.yml

@@ -304,4 +304,36 @@ days:
   "11-26": [st-silvester-abbot, st-peter-of-alexandria]
   "11-29": [vigil-of-st-andrew, st-saturninus]
   "11-30": [st-andrew]
+  # December — 12/12, the final month of the pre-1955 pull. Every
+  # non-excluded date this month falls within a season this app now
+  # models as `privileged-feria-minor` (Advent through Dec 20, Christmas's
+  # own Octave from Dec 26) -- this month's own pull is what surfaced and
+  # verified that temporal-category fix (see calendar/types.ts and this
+  # repo's commit history). Immaculate Conception's own propers were
+  # backfilled this month. Excluded: Dec 24 (Vigil of Christmas) and Dec
+  # 25 (Christmas itself) aren't sanctoral entries at all -- Christmas is
+  # a fixed-date temporal anchor (see data/calendar/fixed-date-
+  # calendar.yml) and its Vigil is a distinct privileged-feria-major
+  # temporal category, neither modeled as a saint. St. Eusebius of
+  # Vercelli (Dec 15) is a monastic-calendar-specific placement, reached
+  # via a same-day redirect notation in M1617.txt rather than a plain
+  # date entry. The Vigil of St. Thomas (Dec 20) always lands on Advent's
+  # Ember Saturday -- a known Mass-vs-Office simplification, same pattern
+  # as September's Vigil of St. Matthew.
+  "12-02": [st-bibiana]
+  "12-04": [st-barbara]
+  "12-05": [st-sabbas]
+  "12-06": [st-nicholas]
+  "12-07": [st-ambrose]
   "12-08": [immaculate-conception]
+  "12-10": [st-melchiades]
+  "12-11": [st-damasus]
+  "12-13": [st-lucy]
+  "12-15": [st-eusebius-of-vercelli]
+  "12-20": [vigil-of-st-thomas]
+  "12-21": [st-thomas-apostle]
+  "12-26": [st-stephen-protomartyr]
+  "12-27": [st-john-apostle]
+  "12-28": [holy-innocents]
+  "12-29": [st-thomas-becket]
+  "12-31": [st-silvester-i]

src/data/calendar/temporal-categories.yml

@@ -39,10 +39,15 @@ bySeason:
   # comment) -- weaker than the Ember-day `privileged-feria` tier, but real
   # standing nonetheless, unlike a plain `ordinary-feria`.
   advent: { sunday: privileged-sunday, feria: privileged-feria-minor }
-  # Christmastide's ferias are folded into the privileged-feria default for
+  # Christmastide's ferias are folded into the privileged-feria-minor
-  # the whole season as a simplification of "the Octave of Christmas (Dec
+  # default for the whole season as a simplification of "the Octave of
-  # 25 - Jan 1) is privileged" — slightly overbroad into Jan 2-5, harmless.
+  # Christmas (Dec 25 - Jan 1) is privileged" — slightly overbroad into Jan
-  christmastide: { sunday: privileged-sunday, feria: privileged-feria }
+  # 2-5, harmless. Verified `privileged-feria-minor` specifically (not the
+  # stronger `privileged-feria`) during the December pull: St. Thomas of
+  # Canterbury, Semiduplex, wins outright within the Octave (Dec 29) in the
+  # real Monastic 1617 engine, which `privileged-feria`'s Duplex+ threshold
+  # would wrongly forbid.
+  christmastide: { sunday: privileged-sunday, feria: privileged-feria-minor }
   epiphanytide: { sunday: ordinary-sunday, feria: ordinary-feria }
   septuagesima: { sunday: privileged-sunday, feria: ordinary-feria }
   lent: { sunday: privileged-sunday, feria: ordinary-feria }