fix(ef): the seasonal commemoration comes first (RG 113 sentence one)

"113. Commemoratio de Tempore fit primo loco. In admittendis et ordinandis
aliis commemorationibus, servetur ordo tabellae praecedentiae." Only the
second sentence was implemented, adopted on ef-rg16a as the admission and
ordering criterion. The first -- the commemoration OF THE SEASON is made in
the first place -- was not, so ordering ran through band alone for every
commemoration including the seasonal one.

Reconciled with RG 110(c), which adds the inseparable Peter/Paul pair "ante
omnes alias commemorationes". Both rubrics are primary-source certain: the
photographic scans' OCR is illegible at RG 110(c), but docs/research/LT.txt,
the electronic transcription, carries the Rubricae Generales complete, and
O'Connell's footnote 39 turns out to render that clause exactly rather than
gloss it. They share a technical term. RG 113's own sentence fixes the sense
of "aliae commemorationes" as the ones other than the de Tempore one it has
just placed primo loco, and RG 110(c) sits three paragraphs earlier in the
same code. Read consistently, the pair heads the OTHERS, not the whole list:
season, then the pair, then the table order. So this runs after
rg110_additions, and List.partition's stability keeps the pair adjacent while
the seasonal commemoration steps in front of it.

Blast radius, two full 1583-9999 sweeps diffed: 3 533 days, every one
ORDER-ONLY -- the commemoration set is identical on both sides of every
changed day, checked as sorted multisets, zero days where anything else
moved. All are 22 February with chair-of-st-peter observed. Exactly the
population measured before the rule was written.

The order-sensitive test row is in test_precedence_ef.ml's admit_cases, which
is still the only place in the suite that asserts commemoration order at all.
It needed a mixed-origin candidate: every other candidate in that table is
origin = Temporal by default, so the rule is an identity on them.

1 files changed, 28 insertions, 0 deletions

diff --git a/test/test_precedence_ef.ml b/test/test_precedence_ef.ml
index 790dab6..3f3e070 100644
--- a/test/test_precedence_ef.ml
+++ b/test/test_precedence_ef.ml
@@ -1170,12 +1170,40 @@ let unrelated_comm_synth =
    contest; it adds Paul regardless. *)
 let lent_feria_synth = (cand ~origin:P.Temporal ~rank:V.Class3 "ef-lent-2-monday-synth", P.Privileged, 180)
 
+(* RG 113 sentence ONE (docs/research/rules-register.md §6.26):
+   "Commemoratio de Tempore fit primo loco." The commemoration OF THE SEASON
+   is made in the first place; the second sentence's table order governs the
+   OTHERS. Every other candidate in this table is [origin = P.Temporal] by
+   [cand]'s own default, so the rule is an identity on them and no existing
+   row's expectation moves; these two candidates exist to make a MIXED-origin
+   row possible, which is the only shape that can witness it.
+
+   This file's [admit_cases] is the ONLY place in the whole suite that
+   asserts commemoration ORDER -- the differential never compares
+   commemorations, the oracle sorts both sides into a multiset, and
+   test_golden.ml's own [describe] deliberately sorts its comms field. So a
+   row here is the only thing standing between this rule and a silent
+   regression. *)
+let sanctoral_hi =
+  { (cand ~rank:V.Class2 "ef-sanctoral-hi") with P.origin = P.Sanctoral }
+
+let seasonal_lo = cand ~rank:V.Class3 "ef-seasonal-lo"
+
 let admit_cases =
   [ (* RG 111 (§4): "I class: none save one privileged." *)
     ( "I-class day, only an ordinary commemoration due -> none admitted",
       observed_class1, observed_class1,
       [ po ordinary_hi P.Ordinary ],
       [] );
+    (* RG 113 s1: the de Tempore commemoration leads, even though the
+       sanctoral one outranks it on RG 91's table (Class2 beats Class3) and
+       would therefore come first under sentence TWO alone. Both slots of a
+       III-class day are filled, so this row tests ORDER, not selection. *)
+    ( "III-class day, seasonal + sanctoral both admitted -> the SEASONAL one \
+       first (RG 113 s1), despite the sanctoral one's higher table position",
+      observed_class3, observed_class3,
+      [ po sanctoral_hi P.Ordinary; po seasonal_lo P.Ordinary ],
+      [ "ef-seasonal-lo"; "ef-sanctoral-hi" ] );
     ( "I-class day, ordinary + privileged both due -> only the privileged \
        one, regardless of the ordinary one's higher dignity",
       observed_class1, observed_class1,