Integrations DI refactor, remove Sellasist/Baselinker, fix product-edit encoding (0.263)

- New: Domain\Integrations\IntegrationsRepository + admin\Controllers\IntegrationsController (DI)
- Cleanup: removed all Sellasist and Baselinker integrations from entire project
- Fix: product-edit.php Polish characters (UTF-8/CP1250 double-encoding)
- Update: factory\Integrations as facade (Apilo + ShopPRO only)
- Tests: 212 tests, 577 assertions

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

autoload/admin/factory/class.ShopStatuses.php

@@ -10,15 +10,13 @@ class ShopStatuses {
   }
 
   // status_save
-  public static function status_save( $status_id, $color, $apilo_status_id, $sellasi_status_id, $baselinker_status_id )
+  public static function status_save( $status_id, $color, $apilo_status_id )
   {
     global $mdb;
 
     $mdb -> update( 'pp_shop_statuses', [
         'color' => $color,
         'apilo_status_id' => $apilo_status_id ? $apilo_status_id : null,
-        'sellasist_status_id' => $sellasi_status_id ? $sellasi_status_id : null,
-        'baselinker_status_id' => $baselinker_status_id ? $baselinker_status_id : null
       ], [ 'id' => $status_id ] );
 
     return $status_id;