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- Delete class.Log (unused), class.Mobile_Detect (outdated UA detection)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>

admin/templates/site/unlogged-layout.php

@@ -32,8 +32,8 @@
                   Zaloguj się do panelu administratora <b>shopPro</b>.
                 </div>
                 <?
-                if ( $alert = \S::get_session( 'alert' ) ):
-                  \S::alert( false );
+                if ( $alert = \Shared\Helpers\Helpers::get_session( 'alert' ) ):
+                  \Shared\Helpers\Helpers::alert( false );
                   ?>
                   <div class="alert alert-danger alert-dismissable">
                     <button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>