calendar: real occurrence/precedence resolution (feast ranks, sanctoral content)

Replaces the FeastRank placeholder with a real ordered FeastClass (the old
pre-1955 six-level scale) and a new TemporalCategory (privileged/ordinary
Sunday/feria). calendar/commemorations.ts's decideOccurrence encodes the
actual precedence rules as explicit, commented branches per category
rather than the reference engine's own opaque numeric weights — this app
targets one ruleset, so the readability trade-off is worth it. Category
membership (data/calendar/temporal-categories.yml) is a best-effort
reconstruction of the pre-1955 tradition, not sourced from a primary text;
expect corrections.

calendar/feasts.ts resolves real sanctoral candidates, and resolveDay()
wires it all together — occurring/temporalCategory are no longer stubs.
isDoubleOrHigher (hours/antiphon.ts) is now a real comparison instead of
a hardcoded false.

Seeded 7 real saints/feasts, each verified directly against Divinum
Officium's own rank data (not reconstructed from memory) as a small,
growable start: St. Lawrence, the Assumption, St. Augustine, the Nativity
of the BVM, St. Michael, All Saints, the Immaculate Conception.

src/data/calendar/sanctoral-calendar.yml

@@ -5,8 +5,17 @@
 # (data/calendar/saints/<id>.yml) never changes — it's the same record
 # whichever day points at it.
 #
-# PLACEHOLDER: "01-01" -> example-confessor is fake data proving the shape,
-# not a real calendar assignment. Real sanctoral content-authoring
-# (a pre-1910-leaning calendar, per the plan) is a separate task.
+# A small, growable subset, not a full year — see the plan discussion this
+# came out of. Each entry's rank is verified directly against Divinum
+# Officium (see the saint's own file for which one) rather than
+# reconstructed from memory, unlike data/calendar/temporal-categories.yml's
+# privileged-day lists. `example-confessor` is deliberately NOT mapped to
+# any day here — it's fictional, kept only to document the record shape.
 days:
-  "01-01": [example-confessor]
+  "08-10": [st-lawrence]
+  "08-15": [assumption]
+  "08-28": [st-augustine]
+  "09-08": [nativity-bvm]
+  "09-29": [st-michael]
+  "11-01": [all-saints]
+  "12-08": [immaculate-conception]