feat(ef): the Creed, RG 475-476

Whether the Creed is said at Mass. New Rubrics_ef.creed, reached through
a new Rite.t.creed field and a new Liturgical_day.t.creed bool (false,
not an option, for a rite that has not implemented the rule); colitur
rubrics gains a fourth TAB-separated column.

475(a) reads the TEMPORAL cycle's own weekday, not the observed day: a
Sunday impeded by a Feast of the Lord (RG 16a) still says the Creed.
475(d)'s three octaves (Nativity, Easter, Pentecost) are pure date/
Easter-offset windows, checked first, since a saint's feast winning the
day inside one of them still says the Creed ("etiam in festis
occurrentibus") -- St Stephen, 26 December, is the live witness.

RG 23 classifies Ash Wednesday and every feria of Holy Week (including
the Sacred Triduum) as feriae, not festa, however high their rank, so
475(b)/(c)'s "in festis" never reaches them; this single check subsumes
476(a)'s own naming of the Chrism/Lord's-Supper Mass and the Easter
Vigil. RG 28-34 vigils are a third liturgical-day category, also
excluded from "in festis" regardless of rank -- reuses the already-
exported Precedence_ef.is_vigil rather than a new list.

475(e)'s Apostle/Evangelist natalicia list (creed_apostle_slugs) was
derived by grepping data/ef/sanctoral.sexp directly and checking each
candidate's own date against whether it is that saint's dies natalis --
not copied from any list supplied with the task. The Conversion of St
Paul and the 30 June Commemoration of St Paul are excluded (neither is
a natalicium); the Chair of St Peter and St Barnabas are included only
because the clause names them explicitly, which is exactly why it has
to: neither is a natalicium either.

475(c)'s BVM half reuses Precedence_ef.marian_slugs (newly exported)
rather than the subject field alone: checked against the shipped data,
almost every Marian sanctoral entry ships subject=Saint, not Bvm.

man/colitur.1's rubrics section is updated to match the new column;
test/cli.t repinned via dune promote for the same reason. Verified
day/readings output byte-identical to v0.10.1 across the whole
1583-9999 domain (both binaries' concatenated day+readings output,
6,148,492 lines each, zero diff). Domain-wide: 882,996 days say the
Creed, 2,191,250 do not; every one of the domain's 439,178 Sundays says
it, zero exceptions.

1 files changed, 9 insertions, 3 deletions

diff --git a/test/test_validate.ml b/test/test_validate.ml
index 7387971..ea8fc0f 100644
--- a/test/test_validate.ml
+++ b/test/test_validate.ml
@@ -324,16 +324,22 @@ module Synthetic = struct
     { Colitur_kernel.Mass_formulary.said = Slug.of_string_exn "syn-formulary";
       via = Colitur_kernel.Mass_formulary.Own_slug }
 
+  (* No fixture here exercises the Creed rubric -- a rite that has not
+     implemented it returns [false] explicitly, {!Rite.t.creed}'s own
+     documented default. Made overridable ([?creed] below) on the same
+     footing as [?readings] just above, for Task 6's own fixtures. *)
+  let creed ~temporal:_ ~observed:_ ~date:_ = false
+
   let rite ?(vocab = vocab) ?(anchors = fun _ -> []) ?(season_runs = [ A; B ]) ?(rules = rules)
-      ?(transfer_target = fun _ origin _ -> origin) ?(readings = readings) temporal :
-      (season, rank) Rite.t =
+      ?(transfer_target = fun _ origin _ -> origin) ?(readings = readings) ?(creed = creed) temporal
+      : (season, rank) Rite.t =
     { Rite.id = "synthetic"; vocab; year_start; temporal; anchors; rules; season_runs;
       (* Not a Roman rite, but a Rite.t must supply SOME Easter now that
          movable Date_spec variants exist. The Gregorian one is as good as
          any for a fixture; nothing here is Easter-relative, so the value
          is never actually read. *)
       easter = Colitur_kernel.Computus.gregorian_easter;
-      transfer_target; readings }
+      transfer_target; readings; creed }
 
   (* Empty by default: every check built before Task 12 exercises the
      TEMPORAL-only pass, where an empty layer is exactly the fixture that