calendar: pull October's sanctoral calendar (pre-1955 pull, 10/12)

16 saints (14 real winners + 2 stubs). Three monastic-calendar-specific
finds this month: Ss. Placid and Companions (Oct 5, St. Benedict's own
disciple, Duplex II. classis -- absent from the base Tridentine table
entirely), St. Justina (Oct 7, reassigns what the base table gives to
St. Marcus, Pope), and St. Gall (Oct 16, founder of St. Gallen, also
absent from the base table). No octave-gap exclusions this month.

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

src/data/calendar/saints/ss-placid-and-companions.yml

@@ -0,0 +1,15 @@
+# A monastic-calendar-specific addition: absent from the base Tridentine
+# table (1570.txt) entirely, added by the monastic-specific delta table
+# (M1617.txt) -- fittingly, since St. Placid is St. Benedict's own famous
+# disciple. Verified live (Monastic Tridentinum 1617, 2026-10-05 and
+# again 2032-10-05) -- winner outright, Duplex II. classis, alone; the
+# highest-ranked monastic-only addition found in this pull so far. No
+# unique collect: the raw file's [Oratio] is a plain cross-reference to a
+# generic Common-of-several-martyrs formula (@Commune/C3a), not unique
+# text, so propers: null is correct (Common-of-Saints only), same
+# treatment as any other saint whose own file just points at the Common.
+id: ss-placid-and-companions
+name: "Ss. Placid and Companions, Martyrs"
+rank: duplex-2-classis
+common: common-of-several-martyrs
+propers: null