ver. 0.283: Legacy class cleanup — S, Html, Email, Image, Log, Mobile_Detect → Shared namespace

- Migrate class.S → Shared\Helpers\Helpers (140+ files), remove 12 unused methods
- Migrate class.Html → Shared\Html\Html
- Migrate class.Email → Shared\Email\Email
- Migrate class.Image → Shared\Image\ImageManipulator
- Delete class.Log (unused), class.Mobile_Detect (outdated UA detection)
- Remove grid library loading from admin (index.php, ajax.php)
- Replace gridEdit usage in 10 admin templates with grid-edit-replacement.php
- Fix grid-edit-replacement.php AJAX to send values as JSON (grid.js compat)
- Remove mobile layout conditionals (m_html/m_css/m_js) from Site + LayoutsRepository
- Remove \Log::save_log() calls from OrderAdminService, ShopOrder, Order

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

download.php

@@ -32,7 +32,7 @@ $mdb = new medoo( [
                     'charset'       => 'utf8'
                 ] );
 
-if ( $file_id = \S::get( 'file' ) )
+if ( $file_id = \Shared\Helpers\Helpers::get( 'file' ) )
 {
   $result = $mdb -> get( 'pp_articles_files', [ 'src' ], [ 'id' => $file_id ] );
   if ( $result )