test(differential): split the Holy Family/Baptism collision out of C1 (C15)

Before this task's Holy Family fix, colitur's generic Sunday
fallback lost outright to the fixed Commemoration of the Baptism of
the Lord on 13 January whenever it fell on a Sunday, producing the
SAME slug lectio's own tridentine-calendar.ini shows there --
squarely inside C1's own 6-13 January blanket (only Season differed).
Now that Holy Family (RG 17(b)) correctly outranks the fixed Baptism
and excludes it as a commemoration (RG 91 entry 14, RG 112(a)),
colitur's own slug on those seven dates (2008, 2013, 2019, 2030,
2036, 2041, 2047) changes to ef-time-after-epiphany-sunday-1 -- a
genuine identity divergence against lectio, which has no Holy Family
at all. C1's own predicate does not absorb it (jan_6_13_slug has no
entry for that slug), so it surfaced as unexplained, exactly the
check the task brief asked for: split it out into its own cited
entry rather than widening C1's predicate to swallow it silently.

C1's own expected_rows moves 368 -> 361 (back to its pre-rebootstrap
value, for a third and different reason than either of the first two
moves recorded in its own note); the new C15 covers the 7 rows,
gated on the literal date list AND colitur's own slug, the same
identity guard C1/C6/C8/C14 already apply.

1 files changed, 7 insertions, 2 deletions

diff --git a/data/ef/expected-divergences.sexp b/data/ef/expected-divergences.sexp
index a733273..8e104d9 100644
--- a/data/ef/expected-divergences.sexp
+++ b/data/ef/expected-divergences.sexp
@@ -45,8 +45,8 @@
 ((id C1)
  (citation "RG 72-73 (Nativity/Epiphany season boundary, Jan 1-13) + RG 119a (white through \"expletum tempus Epiphaniae\"); register §3c item 1")
  (verdict colitur)
- (note "6-13 January is Christmastide in colitur, matching RG 72-73's explicit boundary at 13 January (corroborated independently by RG 119a's colour rule, §3b). lectio's efSeason switches to time-after-epiphany on 6 January. The season disagreement cascades into colour (green vs white) and, on 7-8 January specifically, into the ferial slug family name (colitur's ef-christmas-2-<weekday> vs lectio's ef-time-after-epiphany-1-<weekday> for the same two days). REFRESHED (ef-rebootstrap fixture refresh, 2026-08-12): expected_rows moved 361 -> 368. NOT a new divergence -- the closed C13's own 7 rows (13 January in the 7 years it falls on a Sunday) fold back in here: lectio's fix wave independently fixed its own equivalent of the RG16(a) defect C13 used to allow-list, so on all 7 of those Sunday years lectio's slug now matches colitur's `commemoration-of-the-baptism-of-the-lord` too (not just rank/colour), leaving season as the ONLY residual difference on those rows -- squarely inside C1's own existing shape (diffs subset of [Season;Colour;Slug] with the Slug-diff escape clause unused). Re-derived independently (a Python cross-check reading colitur's own `day` CLI output for 2005-2050 and the refreshed lectio fixture directly, replicating diff_fields/layer_c_reason's own logic outside the OCaml comparator, then cross-checked against the OCaml comparator's own `test_layer_c_counts_match_citations` failure output before this entry's value was set -- not by running the comparator green and copying its number): 368.")
- (expected_rows 368))
+ (note "6-13 January is Christmastide in colitur, matching RG 72-73's explicit boundary at 13 January (corroborated independently by RG 119a's colour rule, §3b). lectio's efSeason switches to time-after-epiphany on 6 January. The season disagreement cascades into colour (green vs white) and, on 7-8 January specifically, into the ferial slug family name (colitur's ef-christmas-2-<weekday> vs lectio's ef-time-after-epiphany-1-<weekday> for the same two days). REFRESHED (ef-rebootstrap fixture refresh, 2026-08-12): expected_rows moved 361 -> 368. NOT a new divergence -- the closed C13's own 7 rows (13 January in the 7 years it falls on a Sunday) fold back in here: lectio's fix wave independently fixed its own equivalent of the RG16(a) defect C13 used to allow-list, so on all 7 of those Sunday years lectio's slug now matches colitur's `commemoration-of-the-baptism-of-the-lord` too (not just rank/colour), leaving season as the ONLY residual difference on those rows -- squarely inside C1's own existing shape (diffs subset of [Season;Colour;Slug] with the Slug-diff escape clause unused). REFRESHED AGAIN (ef-rg112-rg110 task, branch ef-rg112-rg110): expected_rows moved 368 -> 361, back to its PRE-ef-rebootstrap value, but for a THIRD, different reason -- SPLIT OUT to its own new entry, C15, not silently re-absorbed: colitur now BUILDS Holy Family (RG 17(b)) and, on these same 7 dates, correctly observes it in the fixed Baptism's place (RG 91 entry 14, RG 112(a)), so colitur's own slug there changes from `commemoration-of-the-baptism-of-the-lord` (which happened to already match lectio's own slug) to `ef-time-after-epiphany-sunday-1` (Holy Family's own, lectio has no equivalent) -- a genuine SLUG divergence now, no longer inside C1's own [Season]-only shape. See C15's own entry for the full account.")
+ (expected_rows 361))
  ((id C6)
  (citation "RG 91 entry 17 (\"days within the Octave of the Nativity\")")
  (verdict colitur)
@@ -62,3 +62,8 @@
  (verdict colitur)
  (note "ef-rebootstrap fixture refresh (2026-08-12), replacing the closed C9's old 'Joseph on a Lent Sunday' shape: in 2008, 2035 and 2046, St Joseph's (19 March) RG 96 walk is congested enough by Passiontide/Holy Week/the Easter octave to cross Easter, landing on the Monday after Low Sunday -- exactly where the Annunciation (25 March), independently transferred under its own Attamen (a) exception, has already been assigned its \"sedes propria\". colitur's calendar.ml (place_transfers/compare_deferred) resolves the resulting same-band (RG 91 entry 11) tie between the two I-class feasts by slug order (\"annunciation...\" < \"joseph...\"), an engineering convention with no direct RG citation of its own (recorded honestly as such in calendar.ml's own comments and test_golden.ml's 2008 golden-pin comment) -- so the Annunciation keeps the Monday and Joseph's own walk continues one day further (1 April 2008; 3 April 2035 and 2046, since the Annunciation's own target there is 2 April), each a genuine free class-4 feria. lectio, by contrast, does NOT resolve this collision at all: its transferIfImpededEF walks each candidate independently with no awareness of a second contestant, so the Annunciation's own walk claims the Monday and Joseph is left with no transferred day anywhere -- merely tacked onto the Annunciation's own row as a trailing, never-admitted \"+joseph-spouse-of-the-bl-virgin-mary\" candidate (lectio's own commit 09a1444, \"calendar: record the RG 95 chained-transfer gap in the source\", states this outright: \"No functional change -- this collision is left unfixed, defensible against scope\"). RG 95 grants the right of translation to I-class feasts; Joseph has it and lectio's engine never exercises it for him here -- colitur giving him a real transferred day, somewhere, is the more textually faithful reading regardless of the harder sub-question below. OPEN SUB-QUESTION, recorded rather than silently resolved either way (docs/research/rules-register.md has the full account): whether Joseph, being impeded FIRST (19 March, six days before the Annunciation's own 25 March), should instead take priority for the Monday under RG 98's \"in paritate autem Officium prius impeditum praecedit\" (at equal table position, the office impeded first takes precedence) -- which would push the ANNUNCIATION to the later day instead. colitur's current slug-order tie-break was never checked against this specific reading; the Annunciation's own \"tamquam in sedem propriam\" wording is offered as the stronger textual argument for exempting it from an RG 97/98 queue contest altogether (it names a specific day as its own proper seat, not a provisional walk target), but this is this project's own reading of the primary text, not a settled point -- flagged as a genuine open item, not adjudicated with full confidence either direction. Independently re-derived (not copied from prose): `grep joseph-spouse-of-the-bl-virgin-mary` against both the refreshed fixture and colitur's own `day` CLI output for 2005-2050, filtered to rows with a real post-Layer-A/B diff -- exactly these 3 dates, cross-checked against the OCaml comparator's own failure output before this value was set.")
  (expected_rows 3))
+ ((id C15)
+ (citation "RG 91 entry 14 (\"Festa Domini II classis, primum mobilia, deinde fixa\") + RG 17(b) (\"festum S. Familiae ... celebrandum dominica prima post Epiphaniam ... locum tenet dominicae occurrentis cum omnibus iuribus et privilegiis\") + RG 112(a) (\"Officium, Missa aut commemoratio de aliquo festo vel mysterio unius Divinae Personae excludit commemorationem ... de alio festo vel mysterio eiusdem Divinae personae\"), all scan-verified; register §6.0/§4")
+ (verdict colitur)
+ (note "ef-rg112-rg110 task: SPLIT OUT of C1's own blanket 6-13 January window, not a new kind of divergence -- the same discipline the now-closed C13 already established for this exact date (C1's own note above), applied again because building Holy Family reopened the identical shape C13 used to cover, for a different underlying reason. Before this task, colitur had no Holy Family office: on these seven dates (13 January when it is itself a Sunday -- 2008, 2013, 2019, 2030, 2036, 2041, 2047), colitur's generic Sunday fallback lost outright to the fixed Commemoration of the Baptism of the Lord (already subject Lord in the rebootstrapped data, RG16(a)'s existing mechanism), producing the SAME slug lectio's own tridentine-calendar.ini shows there (`commemoration-of-the-baptism-of-the-lord`) -- only Season differed, inside C1's own shape. Holy Family (RG 17(b)) now correctly outranks the fixed Baptism (RG 91 entry 14's own \"primum mobilia, deinde fixa\" -- {!Rite_ef.Precedence_ef.entry_14_movable_band}) and excludes it as a commemoration entirely (RG 112(a), directly confirmed by the Holy Family Mass propers' own more specific 13-January rubric, both photographic scans: \"Si festum S. Familiae occurrerit die 13 ianuarii, Missa dicitur de festo S. Familiae, sine commemoratione Baptismatis D.N.I.C., et sine commemoratione dominicae\"), so colitur's own slug on these 7 dates changes to `ef-time-after-epiphany-sunday-1` (Holy Family's own -- unchanged from the plain Sunday key it always carried, temporal_ef.ml's own comment on why) -- a genuine SLUG divergence against lectio, which has no Holy Family at all and still shows the fixed Baptism observed. Gated on the literal 7-date list AND colitur's own slug (the same identity guard C1/C6/C8/C14 already apply, fix round 1's own finding 1). Derived from the OCaml comparator's own failure output directly (test_layer_c_counts_match_citations), not by hand-counting first and cross-checking after: 7.")
+ (expected_rows 7))