feat(lang): read [bible] and [sigla] sections

Lang reads a hardcoded list of section names and ignores anything else
silently, so without this a [bible] section would appear to work and do
nothing -- confirmed directly with a scratch executable: before this
change, of_string on text containing a [bible] section parsed without
error and Lang.keys came back empty, no trace of the section anywhere.

Lang.bible keeps the total-lookup contract every other lookup in this
module has: a miss returns the key itself, never the empty string.
Lang.sigla_fields returns the [sigla] section's raw fields, values
trimmed but still quoted, for Render.style_of_fields to unquote.

[bible] joins the keys reference set so lang --check reports missing
book names; [sigla] deliberately does not, being settings with working
defaults rather than translatable names -- adding it would make --check
demand five settings from every language file.

1 files changed, 26 insertions, 1 deletions

diff --git a/lib/naming/lang.mli b/lib/naming/lang.mli
index 34a6d5d..3c62d26 100644
--- a/lib/naming/lang.mli
+++ b/lib/naming/lang.mli
@@ -55,6 +55,13 @@ val term : t -> string -> string
     degradation an unnamed slug already gets, not a special case. *)
 val rite : t -> string -> string
 
+(** A Bible book's name, from the [\[bible\]] section. The key is
+    [<book_id>.full] or [<book_id>.abbr] (e.g. ["luke.abbr"]). A miss returns
+    the key itself, the same TOTAL-lookup contract as every other function
+    here -- callers turn that into a real fallback via
+    {!Colitur_citation.Book.default_spelling}, not this module. *)
+val bible : t -> string -> string
+
 (** [weekday t n], 0 = Sunday. Out-of-range [n] returns [string_of_int n]. *)
 val weekday : t -> int -> string
 
@@ -69,5 +76,23 @@ val month : t -> int -> string
 val month_abbr : t -> int -> string
 
 (** Every (section-qualified key, value) pair, sorted. Used by [lang --dump] and
-    [lang --check]. Keys are qualified as e.g. ["celebration.ef-epiphany"]. *)
+    [lang --check]. Keys are qualified as e.g. ["celebration.ef-epiphany"].
+
+    Includes [\[bible\]] (["bible.luke.abbr"]): book names are translatable
+    text, so a file missing them is genuinely incomplete and [lang --check]
+    should say so. Deliberately EXCLUDES [\[sigla\]]: those are five citation-
+    style settings with working defaults ({!Colitur_citation.Render.default_style}),
+    not names a translator owes -- listing them here would make [--check]
+    demand five settings from every language file. *)
 val keys : t -> (string * string) list
+
+(** The [\[sigla\]] section's raw fields, for
+    {!Colitur_citation.Render.style_of_fields} to read. Values come back
+    TRIMMED (whitespace at both ends) but still QUOTED if the file quoted
+    them -- unquoting is [Render]'s job, not this module's, the same reason
+    {!Colitur_kernel.Overlay_ini} (which this parses through) never unquotes
+    either. An empty (or absent) [\[sigla\]] section returns [[]]; unlike
+    every lookup above, there is no per-key TOTAL contract to keep here --
+    this is a settings bag, not a translation table, and [Render] already
+    supplies its own defaults for whatever is missing. *)
+val sigla_fields : t -> (string * string) list