bindings: the author a record's own text can offer

book-pipeline had its own copy of bibclean's author recovery. Bound on all
four surfaces so it can stop.

Checked against that Python over all 5,385 books in the library: 5,375
identical. On the other ten the Python had taken a translator, an illustrator
or the publisher off a copyright line — Sally-Ann Spencer for *The Dwarves*,
Thomas Nelson for a table of contents, C. S. Lewis for a book about Tolkien —
and bibclean either finds the real author in the Library of Congress block or
says nothing. Every one of the ten was read by hand.

crates/bindings/include/catena.h

@@ -98,6 +98,11 @@ char *catena_series_of(const char *title, const char *author);
  * one — an answer, not an error. */
 char *catena_parse_identifier(const char *text);
 
+/* The best author a record's own title and front matter can offer. Returns a
+ * JSON suggestion, or NULL when neither names a person — an answer, not an
+ * error. `front_matter` may be NULL. */
+char *catena_suggest_author(const char *title, const char *front_matter);
+
 /* Whether a chunk of body text carries footnote or endnote citations.
  * Returns 1 for yes, 0 for no, -1 on error. */
 int catena_looks_like_footnote_citations(const char *text);