ef(lectionary): fix round 1 -- correct a wrong test, a wrong comment, and ba0adba's own wrong commit body

Three Important findings, all traceable to the task-5 brief rather than
the implementation itself; all confirmed against the real data and the
real resolver before fixing, not taken on trust.

1. test_step3_uses_temporal_not_observed (2028-12-26) did not exercise
   step 3 at all: 26 December is always Stephen, a real sanctoral entry
   with its own citations, so that date resolves entirely at step 1.
   Its justifying comment was also wrong -- 24 December's TEMPORAL slug
   is ef-nativity-vigil, IDENTICAL to its observed slug (Temporal_ef.named
   hard-codes the Vigil for that date ahead of any Sunday computation),
   so there was never a temporal/observed split on that date to exploit.
   Replaced with 2025-02-03: 2 February 2025 (Sunday) is observed as the
   Purification (own citations Mal 3:1-4 / Luke 2:22-32) but its TEMPORAL
   identity is ef-time-after-epiphany-sunday-4 (Rom 13:8-10 / Matt
   8:23-27, a different lectionary entry); 3 February has no proper of
   its own and reaches step 3, which must return the Sunday's TEMPORAL
   reading, not the Purification's. Verified against
   data/ef/sanctoral.sexp and data/ef/lectionary.sexp directly.

2. The termination-argument comment in lectionary_ef.ml (and its echo in
   lectionary_ef.mli) claimed an unguarded Sunday would loop. It would
   not: readings is not recursive -- step 3's fallback is one flat
   Lectionary.find, never a re-entrant call into readings -- so an
   unguarded Sunday would just repeat step 2's own already-failed lookup
   once (same pure inputs, same None) and return [] normally. Rewritten
   to say what is actually true: the guard exists because a Sunday has
   no PRECEDING Sunday to resume, not because skipping it would be
   dangerous; the chain terminates because every step consults data or a
   strictly earlier date, and no step ever calls back into readings.

3. Correcting the record, per instruction, rather than amending
   ba0adba: that commit's own body said Advent ferias carry 'Advent I's
   own readings copied onto the following Monday-Thursday'. Both details
   are wrong, verified directly against data/ef/lectionary.sexp: the
   duplicated readings are ef-advent-SUNDAY-2's (Rom 15:4-13 / Matt
   11:2-10), not Advent I's, and they appear on ef-advent-2-monday,
   -tuesday, -thursday and -saturday -- four non-contiguous days, not a
   Monday-to-Thursday span. The in-code comment and the task-5 brief's
   own commit template both already said 'Advent II' correctly; only
   ba0adba's commit body had the error.

dune test --force: 344 tests, all green (unchanged count -- one test's
body changed, none added or removed).

0 files changed, 0 insertions, 0 deletions