feat(domain): Domain\Authors + Domain\Newsletter repositories z wrapper delegation

Phase 4 complete:
- AuthorsRepository: simpleList, authorDetails, authorSave, authorDelete, authorByLang
- NewsletterRepository: 14 methods — subscriber lifecycle, templates, sending
- 4 legacy factories converted to thin wrappers
- Globals ($settings, $lang) passed as explicit params to repo methods

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

autoload/front/factory/class.Authors.php

@@ -1,4 +1,4 @@
-<?
+<?php
 namespace front\factory;
 class Authors
 {
@@ -6,17 +6,7 @@ class Authors
   static public function get_single_author( $id_author )
   {
     global $mdb;
-
-    if ( !$author = \Cache::fetch( "get_single_author:$id_author" ) )
-    {
-      $author = $mdb -> get( 'pp_authors', '*', [ 'id' => (int)$id_author ] );
-
-      $results = $mdb -> select( 'pp_authors_langs', '*', [ 'id_author' => (int)$id_author ] );
-      if ( is_array( $results ) ) foreach ( $results as $row )
-        $author['languages'][$row['id_lang']] = $row;
-
-      \Cache::store( "get_single_author:$id_author", $author );
-    }
-    return $author;
+    $repo = new \Domain\Authors\AuthorsRepository($mdb);
+    return $repo->authorByLang($id_author);
   }
 }