calendar: pull January's sanctoral calendar (pre-1955 pull, 1/12)

20 saints for January, verified per-day against Divinum Officium (Monastic
Tridentinum 1617): 13 that actually win their day outright (rank pulled
from a live per-date query, since the static 1570/M1617 calendar text
files turned out unreliable once monastic-specific overrides apply) and
7 stubs for saints that only ever get commemorated, with an explicitly
flagged, unverified simplex rank guess pending correction.

Deliberately out of scope: pure octave-continuation days (In Octava S.
Stephani, the Epiphany-octave ferias) and fixed-date feasts of the
Lord/BMV (Circumcision, Epiphany) — sanctoral only, not temporal.

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

src/data/calendar/saints/st-maurus-abbot.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live kalendar
+# check (2029-01-15, no Sunday collision) -- winner outright, Duplex II. classis,
+# a monastic-calendar-specific elevation (the base 1570 Tridentine calendar has
+# him as a lesser commemoration on this date instead -- see M1617.txt's delta).
+# No unique Oratio/Antiphon in the source (web/www/horas/Latin/Sancti/01-15.txt
+# has only Lectio blocks) -- he uses the Common of an Abbot for everything.
+id: st-maurus-abbot
+name: "St. Maurus, Abbot"
+rank: duplex-2-classis
+common: common-of-an-abbot
+propers: null