calendar: pull August's sanctoral calendar (pre-1955 pull, 8/12)

18 saints (14 real winners + 4 stubs), plus propers-slug updates for the
4 pre-existing August entries. Notable this month: several dates have a
real named secondary saint permanently subordinate to an unmodeled fixed
octave (Lawrence's own, the Assumption's) or the fixed Transfiguration --
excluded entirely rather than guessed at, since this app can't yet
represent the actual blocking primary (a known, deferred octave gap).
Most notable casualty: St. Clare (Aug 12).

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

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

@@ -0,0 +1,12 @@
+# A real vigil (2025-08-23, clean year -- St. Bartholomew's own date, Aug
+# 24, isn't a Sunday that year either). No unique collect: the raw file at
+# this MM-DD slot (Sancti/08-23.txt) is actually St. Philip Benizi's (a
+# later, post-1617 addition to this filename slot) -- a live prayTertia
+# query for the Monastic 1617 track returns no Oratio at all, confirming
+# propers: null is correct, same file-naming caution as St. Donatus and
+# the Vigil of St. Lawrence this month.
+id: vigil-of-st-bartholomew
+name: "Vigil of St. Bartholomew"
+rank: vigil
+common: common-of-a-vigil
+propers: null