API REST: filtro por idioma en /wp/v2/animals (?lang=es|eu)

- Polylang gratuito no filtra la API REST por idioma: el parámetro «lang» se pasa a la consulta.
- MCP: list_animals descarta además las fichas de otro idioma (funciona aunque WordPress aún no
  esté actualizado).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mcp/src/tools.js

@@ -74,7 +74,7 @@ export function createBilagunServer({ api, publicUrl, remote = false }) {
     params.set('status', includeDrafts ? 'publish,draft,pending' : 'publish');
     if (search) params.set('search', search);
     if (species) params.set('species', String(await speciesId(species, language)));
-    let animals = (await api(`/wp/v2/animals?${params}`)).map(summary);
+    let animals = (await api(`/wp/v2/animals?${params}`)).map(summary).filter((a) => a.language === language);
     if (status) animals = animals.filter((a) => a.profile?.status === status);
     return animals.map(({ id, name, wpStatus, profile, translationOf }) => ({ id, name, wpStatus, status: profile?.status, featured: profile?.featured, age: profile?.labels?.age, translationOf }));
   }));

wp-content/mu-plugins/gure-ametsa/api.php

@@ -336,6 +336,16 @@ add_action( 'graphql_register_types', function () {
 	) );
 } );
 
+/* REST: «?lang=es|eu» en /wp/v2/animals (Polylang gratuito no filtra la API REST por idioma). */
+add_filter( 'rest_animal_collection_params', function ( $params ) {
+	$params['lang'] = array( 'type' => 'string', 'enum' => array( 'es', 'eu' ), 'description' => 'Only animals in this language.' );
+	return $params;
+} );
+add_filter( 'rest_animal_query', function ( $args, $request ) {
+	$args['lang'] = $request['lang'] ?: '';
+	return $args;
+}, 10, 2 );
+
 /* GraphQL: «where: { language, adoptionStatus }» en la consulta de animales («status» ya es el estado de publicación de WordPress). */
 add_filter( 'graphql_post_object_connection_query_args', function ( $args, $source, $input ) {
 	if ( 'animal' !== ( $args['post_type'] ?? '' ) && array( 'animal' ) !== ( $args['post_type'] ?? '' ) ) {