test(differential): fix round 1 -- Holy Week, Lent Ember, RG 69

Two Critical findings, both real: Holy Week (including the entire Sacred
Triduum) was reading Passion Week's Masses -- the original colitur_keys
widened lectio's single, conflated ini section into both weeks instead of
Passion week alone. Narrowed to Passion week only; Holy Week's own four
cleanest days (Monday, Tuesday, Thursday, Saturday) are hand-authored
directly from the Missal, verified twice against both scans (C23); Holy
Wednesday and Good Friday are genuinely multi-lesson liturgies with no
single Epistle slot and are deliberately left unanswered, not guessed (C24).

The Lenten Ember days were still dead keys: Temporal_ef computes
ef-lent-ember-{wed,fri,sat}, lectio's ini names the same data
ef-lent-1-{wednesday,friday,saturday}, and colitur_keys never translated
it -- both engines independently fell through to the same wrong ferial
answer, so even the differential stayed green (C22, a genuine lectio bug
recorded for upstream). Fixed the instance and the class: colitur_keys
gained the rename, and tools/bootstrap_lectionary.ml gained
assert_reachable, sweeping Rite_ef.Temporal_ef.temporal at generation time
so a translation table entry naming a slug colitur never computes dies
loudly instead of shipping silently, plus an informational log of every
real slug with no entry at all.

C21 ("colitur's step 3 cannot reach a correct answer for the fixed
Christmastide slugs") is retired, superseded rather than merely patched:
the Nativity-Octave days now have their own direct Missal formulary
(Tit. 3,4-7/Luc. 2,15-20, "Diebus infra octavam Nativitatis Domini"),
resolved at step 2, not step 3 at all. That surfaced a real RG 69 gap
underneath it: a Sunday landing 26-31 December should keep its own Office,
not the fixed weekday placeholder, which Temporal_ef does not currently
distinguish. C6's verdict is re-opened (open, not colitur) for the 19 of
its 138 rows where this applies directly, and a new entry C25 (57 rows)
records the same gap propagating one hop further through step 3 into Holy
Name week. Both are out of this task's own scope -- a behaviour change to
a shared, multi-round-reviewed kernel-adjacent function -- and recorded,
not fixed, per the coordinator's own instruction.

C6's own note is rewritten in full rather than layered with another
correction; C18's stale trailing count is fixed to match its own pin; the
Vigil-misapplication risk flagged as a Minor closed itself once the
Nativity-Octave fix landed, confirmed by inspection rather than assumed.

dune test: 358/358. COLITUR_EXHAUSTIVE_SWEEP=1 dune test --force: 359/359.

1 files changed, 21 insertions, 2 deletions

diff --git a/test/test_lectionary_ef.ml b/test/test_lectionary_ef.ml
index 71888e3..51c3233 100644
--- a/test/test_lectionary_ef.ml
+++ b/test/test_lectionary_ef.ml
@@ -146,11 +146,30 @@ let test_step3_advent_feria_resumes_sunday () =
     [ "Rom 13:11-14"; "Luke 21:25-33" ]
     (refs (day 2025 12 1))
 
+(* Task 8, fix round 1 (coordinator review, Important 3(a)): this test used
+   to pin 2025-12-29 (a Monday), reached by resuming its preceding Sunday's
+   temporal identity. That date no longer exercises step 3 at all --
+   tools/bootstrap_lectionary.ml's own [nativity_octave_entries] now gives
+   the fixed Nativity-Octave slug (RG 91 entry 17, "ef-nativity-octave-
+   day-5") its OWN direct citation ("Diebus infra octavam Nativitatis
+   Domini", Tit. 3,4-7/Luc. 2,15-20), so 29 December resolves at STEP 2,
+   unconditionally, regardless of weekday. Every civil day in 29-31
+   December now resolves the same way -- there is no date left in that
+   specific window this test could use to exercise step 3.
+
+   Replaced with 2028-01-05 (a Wednesday in Holy Name week, "ef-christmas-
+   1-wednesday"), which still has no citation of its own and genuinely
+   resumes ITS preceding Sunday, 2028-01-02 -- confirmed a real Sunday
+   that year, and confirmed to be Holy Name Sunday specifically (its own
+   [ef-holy-name-sunday] slug, RG 17(a)), not a coincidence: the whole
+   POINT of this test is a Christmas-season feria genuinely falling
+   through to step 3, and this is the closest remaining civil-calendar
+   case to the original 29-31 December window that still does. *)
 let test_step3_christmas_feria_resumes_sunday () =
   Alcotest.(check (list string))
-    "Monday after the Sunday within the octave of Christmas"
+    "Wednesday of Holy Name week resumes Holy Name Sunday's Mass"
     [ "Gal 4:1-7"; "Luke 2:33-40" ]
-    (refs (day 2025 12 29))
+    (refs (day 2028 1 5))
 
 (* Fix round 1 (coordinator review, Important finding 1): the original test
    here (2028-12-26) did not exercise step 3 at all -- 26 December is always