fix: audit findings — parser strictness, name ambiguity, and errors

Found by auditing the shipped program rather than the diff.

The parser accepted OCaml integer-literal syntax, so "Luke 1_1:5" read as
chapter ELEVEN and "+5" as 5 -- a typo silently becoming a different
chapter, reachable through any user overlay. Numbers are now plain digits
and positive, and a descending range is rejected: 1:20-10 is always a
transcription error. No shipped citation changed.

FOUR PAIRS OF DIFFERENT BOOKS SHARED A FULL TITLE. 1 and 2 Corinthians
both rendered "Epistola ad Corinthios", as did Thessalonians, Timothy and
Peter -- 108 citations in 2027 alone that a reader cannot resolve to a
book. This is the Kings defect fixed earlier and not generalised. The
titles now carry their volume numeral, marked CONSTRUCTED, and a test
asserts no two books share a name -- while allowing the case where two
ids ARE the same book under different numbering, which a tradition
relates.

Spec section 8.5 is now delivered rather than merely recorded. Shipped
styles did not re-parse their own output: 32 of 52 Latin abbreviations
and 49 of 52 full titles failed, so a citation copied from colitur's own
output into an overlay was passed through untouched and printed in the
wrong language, silently. Every shipped name is registered as a spelling
and split_book learned multi-word titles by longest-token match. Now 0
of 52 fail beyond the same-book aliases.

Overlay errors were written for a compiler author: they named an OCaml
source file the reader does not have and buried the useful token. The
existing five-path rewriter is replaced by a generic one, applied to
every load path rather than one, so "rank: is not one of the allowed
values (at Class9)" replaces the raw Of_sexp_error dump.

Also: the new-overlay scaffold documented citations and layer without
showing them, and its comment implied the wrong nesting -- the single
easiest thing to get wrong; error messages echoed whole file lines,
copying an unrelated file's contents into stderr when a flag pointed at
one; and config --show validated partway down its table, exiting 2 after
writing five rows to stdout.

1 files changed, 5 insertions, 5 deletions

diff --git a/test/cli.t b/test/cli.t
index b44a256..fe18800 100644
--- a/test/cli.t
+++ b/test/cli.t
@@ -1374,12 +1374,12 @@ fallback: `Colitur_citation.Render.with_book` takes a closed variant, not an
 arbitrary string, so anything other than "full"/"abbr" could never mean
 anything downstream.
 
+STDOUT STAYS EMPTY. The check used to happen partway down the table, so this
+exited 2 having already written five rows -- a caller redirecting stdout to a
+file got a truncated but plausible-looking report beside a non-zero status.
+Validation now runs before anything is printed.
+
   $ XDG_CONFIG_HOME=xdg-sigla colitur config --show --sigla-book bogus
-  config file: xdg-sigla/colitur/config.ini (not found)
-  lang             la                       (default)
-  template         (none)                   (default)
-  format           (none)                   (default)
-  sigla_style      la                       (default)
   colitur: unknown --sigla-book "bogus" (want "full" or "abbr")
   [2]