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/st-zephyrinus.yml

@@ -0,0 +1,11 @@
+# Verified against Divinum Officium (Monastic Tridentinum 1617), live
+# kalendar check (2025-08-26) -- winner outright, Simplex, alone. Own
+# proper collect (source's own English translation drops a mid-word "e" of
+# "example" at a line break in both the raw file and the live query --
+# corrected here as a transcription artifact, same judgment call as
+# April's st-robert.yml name-form correction).
+id: st-zephyrinus
+name: "St. Zephyrinus, Pope and Martyr"
+rank: simplex
+common: common-of-a-martyr-bishop
+propers: "st-zephyrinus"