fix(lang): stop internal book ids reaching output, and finish the docs

Three defects, all found by running the documented examples rather than
by reading code.

All seven modern-numbering targets carried their own internal id as
their Latin name (kings_1.full = kings_1), so --sigla-tradition modern
printed "kings_1 19:3-8" -- leaking a key book.mli states is never shown
to a reader. They now carry Vulgate-derived Latin names marked
CONSTRUCTED: the 1962 Missal uses Vulgate numbering throughout, so it
can contain no incipit for a book that exists only under a later
convention. In Latin the modern tradition therefore only moves Kings and
Esdras; Osee, Ionas, Ecclesiasticus and the Apocalypse keep their names
either way, since modern numbering is a vernacular convention.

The coverage test could not catch this. It compares a name against its
KEY ("kings_1.full"), and "kings_1" differs from that, so the row
passed. A second check now asserts no name IS its own id. The two are
complementary: one catches a missing row, the other a row present but
filled with the wrong thing. Mutation-proved.

--help still claimed sigla settings were resolved "but not yet
rendered", stale since the render wiring landed. colitur-config.5
documented none of the three settings even though config --show prints
them.

1 files changed, 4 insertions, 3 deletions

diff --git a/bin/main.ml b/bin/main.ml
index 5ad3132..c76a082 100644
--- a/bin/main.ml
+++ b/bin/main.ml
@@ -1267,9 +1267,10 @@ naming:
             `abbr`), the same discipline as an unknown `--lang`; an
             unrecognised `--sigla-tradition` is not -- it degrades to the
             Vulgate with a stderr warning, because asking for a renumbering
-            is optional the way asking for a language is not. Settings
-            only, for now: this build resolves and reports them but does
-            not yet render a citation through them.
+            is optional the way asking for a language is not. `--raw`
+            bypasses all of it and emits each citation exactly as stored,
+            byte for byte, so it stays usable for diffing and does not
+            depend on the citation parser being correct.
 
   colitur lang --list         which language files this build can find, and
                                each one's own declared fallback, if any.