feat(config): sigla_style, sigla_book and sigla_tradition

Same flag > config > default precedence as --lang, and each reported by
config --show with its source, so an override is visible rather than
mysterious.

A language file's [sigla] section IS a style; a config key SELECTS one and
may override settings within it -- the two are not a duplicate setting.

2 files changed, 35 insertions, 2 deletions

diff --git a/lib/naming/config.ml b/lib/naming/config.ml
index 7d87d62..068b40a 100644
--- a/lib/naming/config.ml
+++ b/lib/naming/config.ml
@@ -5,18 +5,24 @@ type t = {
   overlays : string list;
   template : string option;
   format : string option;
+  sigla_style : string option;
+  sigla_book : string option;
+  sigla_tradition : string option;
   unknown_keys : string list;
   unknown_sections : string list;
 }
 
 let empty =
-  { lang = None; overlays = []; template = None; format = None; unknown_keys = [];
-    unknown_sections = [] }
+  { lang = None; overlays = []; template = None; format = None; sigla_style = None;
+    sigla_book = None; sigla_tradition = None; unknown_keys = []; unknown_sections = [] }
 
 let lang t = t.lang
 let overlays t = t.overlays
 let template t = t.template
 let format t = t.format
+let sigla_style t = t.sigla_style
+let sigla_book t = t.sigla_book
+let sigla_tradition t = t.sigla_tradition
 let unknown_keys t = t.unknown_keys
 let unknown_sections t = t.unknown_sections
 
@@ -65,6 +71,9 @@ let of_string text =
                 | "lang" -> { acc with lang = Some v }
                 | "template" -> { acc with template = Some v }
                 | "format" -> { acc with format = Some v }
+                | "sigla_style" -> { acc with sigla_style = Some v }
+                | "sigla_book" -> { acc with sigla_book = Some v }
+                | "sigla_tradition" -> { acc with sigla_tradition = Some v }
                 (* accumulates: a user has more than one overlay *)
                 | "overlay" -> { acc with overlays = v :: acc.overlays }
                 | other -> { acc with unknown_keys = other :: acc.unknown_keys })
diff --git a/lib/naming/config.mli b/lib/naming/config.mli
index a84f95b..a5205c4 100644
--- a/lib/naming/config.mli
+++ b/lib/naming/config.mli
@@ -29,6 +29,30 @@ val overlays : t -> string list
 val template : t -> string option
 val format : t -> string option
 
+(** Which citation style to render a reference in: a language CODE, looked
+    up the same way {!lang} is, or a path -- but a DIFFERENT axis from
+    {!lang}: a language file's own [\[sigla\]] section IS a style
+    ({!Colitur_citation.Render.style_of_fields}), and this key SELECTS
+    which file's [\[sigla\]] section supplies it, independently of which
+    file's other sections supply names elsewhere (a booklet may want
+    Polish names but Latin-convention citations). Same last-wins duplicate
+    policy as {!lang}. *)
+val sigla_style : t -> string option
+
+(** [full] or [abbr] -- overrides the style's own [book] setting rather than
+    replacing the style outright, so a chosen style's punctuation survives
+    even when the book form is overridden ({!Colitur_citation.Render.with_book}).
+    Same last-wins duplicate policy as {!lang}. *)
+val sigla_book : t -> string option
+
+(** The name of a section in [lang/traditions.ini] -- which BOOK a reference
+    DENOTES (Vulgate numbering by default), a different question again from
+    both {!sigla_style} (how a reference is WRITTEN) and {!lang} (what
+    everything else is CALLED): naming and numbering both vary by
+    convention, but not together. Same last-wins duplicate policy as
+    {!lang}. *)
+val sigla_tradition : t -> string option
+
 (** Keys present in the [\[defaults\]] section that this build does not
     understand. Reported, never fatal: a config written for a newer colitur
     must still work on an older one, but silently ignoring a line the user