ver. 0.289: ShopCategory + ShopClient frontend migration to Domain + Views + Controllers

ShopCategory: 9 frontend methods in CategoryRepository, front\Views\ShopCategory (3 methods),
deleted factory + view, updated 6 callers, +17 tests.

ShopClient: 13 frontend methods in ClientRepository, front\Views\ShopClient (8 methods),
front\Controllers\ShopClientController (15 methods + buildEmailBody helper),
deleted factory + view + controls, updated 7 callers, +36 tests.

Security fix: removed hardcoded password bypass 'Legia1916'.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/stubs/Helpers.php

@@ -6,6 +6,9 @@ class Helpers
     public static function seo($str) { return $str; }
     public static function delete_dir($path) {}
     public static function alert($msg) {}
+    public static function error($msg) {}
+    public static function lang($key) { return $key; }
+    public static function delete_session($key) { unset($_SESSION[$key]); }
     public static function htacces() {}
     public static function delete_cache() {}
     public static function get($key) { return null; }