merge: celebrant Mass rubrics, and four rubrical corrections

colitur now prints what a real ordo prints for the Mass: which formulary is
said and how it was reached, the Gloria, the Creed, the preface, and the
commemorations with their Low-Mass/sung distinction. colitur rubrics joins
day and readings.

Four defects were found and fixed on the way, each by an external witness
rather than by inspection: the Creed said at Requiem Masses (RG 476(f)),
the missing bissextile shift of St Matthias and St Gabriel (2 041 leap
years), Rogation Monday and Tuesday coloured violet in Paschaltide (RG
119(b)), and the ferias after the Ascension resuming the wrong Sunday's
Mass rather than the Ascension's.

Validation gained a sixth layer and then some: the preface is checked
against three independent publishers over seven witness-years (FIUV, three
LMS editions, three extraordinaryform.org editions), none of which shares
the Divinum Officium -> missalemeum -> lectio lineage the older layers all
descend from.

1 files changed, 46 insertions, 1 deletions

diff --git a/test/test_oracle.ml b/test/test_oracle.ml
index f1d1a89..01938e1 100644
--- a/test/test_oracle.ml
+++ b/test/test_oracle.ml
@@ -1381,6 +1381,33 @@ let m26_dates =
    citation fields are not, discovered by this task). *)
 let m27_dates = [ "2026-12-25"; "2027-12-25" ]
 
+(* M31 (celebrant-rubrics-phase1, Bug 2, 2026-08-22) -- the six ferias
+   between the Ascension and the Friday before the Vigil of Pentecost that
+   repeat the Ascension's own Mass by an explicit marginal rubric in the
+   Proprium de Tempore (data/ef/lectionary.sexp's own [ascension_week_
+   entries], full citation there and in this file's sibling
+   data/ef/expected-divergences.sexp's own C41). Only three of the six
+   civil dates this window's own [c_date] range can reach are actually
+   unoccupied in 2026-2027: 2026-05-21, 2026-05-22 and 2027-05-14 (the
+   other three fall to a real sanctoral feast both engines already agree
+   on). missalemeum -- Divinum Officium's own lineage, the SAME lineage
+   lectio inherited this defect from before colitur's own bootstrap --
+   still walks these ferias back to the preceding Sunday's Mass, the
+   pre-fix answer colitur itself used to give; [Observed_identity_
+   unresolved] fires alongside because none of the three is a SANCTORAL-
+   origin day (the mapping this whole file's own header describes cannot
+   name a TEMPORAL office's title either way, unrelated to this cause). *)
+let m31_dates = [ "2026-05-21"; "2026-05-22"; "2027-05-14" ]
+
+(* The exact six slugs data/ef/lectionary.sexp's own [ascension_week_entries]
+   answers -- reused by [classify_2038]/[classify_2035] below, which key on
+   slug identity rather than a date list (those two live windows are not
+   scoped the way the 2026-2027 fixture is). *)
+let ascension_week_slugs =
+  [ "ef-easter-6-friday"; "ef-easter-7-monday"; "ef-easter-7-tuesday"; "ef-easter-7-wednesday";
+    "ef-easter-7-thursday"; "ef-easter-7-friday"
+  ]
+
 (* The oracle's own row went unused when M2 -- its one reader, via
    [o.o_title] -- was closed/removed (see the comment above [m1_dates]), and
    was kept as a named, typed parameter rather than dropped from the
@@ -1512,6 +1539,8 @@ let layer_m_reason (c : colitur_row) (o : oracle_row) diffs =
                [ Rank; Colour_f; Comm_presence; Comm_count; Observed_identity_mismatch;
                  Comm_identity_unresolved; First_mismatch; Gospel_mismatch ]
   then Some "M30"
+  else if List.mem c.c_date m31_dates && subset diffs [ Observed_identity_unresolved; First_mismatch; Gospel_mismatch ]
+  then Some "M31"
   else None
 
 (* ---------------------------------------------------------------------- *)
@@ -1992,6 +2021,16 @@ let classify_2038 (c : colitur_row) (o : oracle_row) diffs =
     List.mem c.c_date [ "2035-08-09"; "2035-08-14"; "2038-08-09"; "2038-08-14" ]
     && diffs = [ Colour_f ]
   then Some "VIGIL-COLOUR-RG128 (M29, colitur; see C37)"
+  (* The Ascension-repeat rubric (celebrant-rubrics-phase1, Bug 2; see M31
+     in this file's own 2026-2027 [layer_m_reason] and C41 in
+     data/ef/expected-divergences.sexp for the full citation). 2038 carries
+     three unoccupied instances the 2026-2027 window did not (2038-06-07/
+     08/09, all week-7 weekdays); 2035 carries one (2035-05-08). Gated on
+     colitur's own slug rather than on the date list this window's sibling
+     windows use, the same style [m21_2038_slugs] already establishes for
+     a live-window slug-keyed class. *)
+  else if List.mem c.c_observed_slug ascension_week_slugs && diffs = [ First_mismatch; Gospel_mismatch ] then
+    Some "ASCENSION-WEEK-REPEAT (M31, colitur; register, Bug 2)"
   else None
 
 (* COMMEMORATIONS join the live-window comparison (2026-08-18).
@@ -2129,7 +2168,13 @@ let test_2038_class_counts () =
         ("MISSAL-TWO-PART-CITATION (register 6.9)", 1);
         ("COMM-IDENTITY-UNRESOLVED (temporal-origin, no English name -- M15's limit)", 2);
         ("PERPETUA-COMMON (register 6.8)", 1);
-        ("PETER-COMPANION-ABSENT-UPSTREAM (M19)", 1)
+        ("PETER-COMPANION-ABSENT-UPSTREAM (M19)", 1);
+        (* celebrant-rubrics-phase1, Bug 2: 2038-06-07/08/09 (the Monday,
+           Tuesday and Wednesday of the week after the Sunday after the
+           Ascension) are unoccupied that year, all three landing on the
+           Ascension-repeat rubric -- see M31 (2026-2027 window) and C41
+           (data/ef/expected-divergences.sexp) for the full citation. *)
+        ("ASCENSION-WEEK-REPEAT (M31, colitur; register, Bug 2)", 3)
       ]
     |> List.sort compare
   in