calendar: pull July's sanctoral calendar (pre-1955 pull, 7/12)

23 saints for July (18 real + 5 stubs). Caught and corrected a real
mistake in this pull's own methodology: an earlier live-query pass
recorded St. Apollinaris under July 24 based on a year where he'd
actually transferred there (his true date, the 23rd, was a Sunday that
year) — cross-checking against the raw calendar text file
(1570.txt) caught it before it went in. His real date is the 23rd, with
St. Liborius as his (permanently unwinnable) secondary; July 24 is
instead the Vigil of St. James with St. Christina as its own secondary.

Five stubs this month are all genuinely unwinnable (fixed-date
competitors) — the most of any month so far.

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

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

@@ -0,0 +1,14 @@
+# Secondary commemoration on 07-23, pulled from Divinum Officium's
+# kalendar headline (Monastic Tridentinum 1617) -- loses the day to
+# St. Apollinaris (also a fixed July 23 saint, not movable -- see st-apollinaris.yml), so unlike most other stubs
+# in this set, this isn't just an artifact of the specific year
+# checked: their competing observance is likewise fixed-date, meaning
+# no year exists where they'd win independently. That query doesn't
+# expose a secondary entry's own rank, only its name -- simplex here
+# is an unverified placeholder, same caveat as every other stub. No
+# text pulled at all yet.
+id: st-liborius
+name: "St. Liborius, Bishop and Confessor"
+rank: simplex
+common: common-of-a-confessor-bishop
+propers: null