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- Delete class.Log (unused), class.Mobile_Detect (outdated UA detection)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

templates/shop-product/_partial/product-attribute.php

@@ -4,11 +4,11 @@ $attribute_details = \front\factory\ShopAttribute::attribute_details( $this -> a
 if ( $attribute_details['type'] == 0 )
 {
   ?>
-    <div class="attribute-container fradio-group attribute-<?= \S::seo( $attribute_details['language']['name'] );?>" level="<?= $this -> level;?>" order="<?= $this -> order;?>" attribute="<?= \S::seo( $attribute_details['language']['name'] );?>" attribute-name="<?= $attribute_details['language']['name'];?>">
+    <div class="attribute-container fradio-group attribute-<?= \Shared\Helpers\Helpers::seo( $attribute_details['language']['name'] );?>" level="<?= $this -> level;?>" order="<?= $this -> order;?>" attribute="<?= \Shared\Helpers\Helpers::seo( $attribute_details['language']['name'] );?>" attribute-name="<?= $attribute_details['language']['name'];?>">
       <p class="attribute-label"><?= $attribute_details['language']['name'];?>:</p>
       <? foreach ( $this -> attribute['values'] as $value ):?>
         <div class="fradio">
-          <input type="radio" id="<?= $this -> attribute['id'];?>-<?= $value['id'];?>" <? if ( $value['is_default'] ):?>checked="checked"<? endif;?> require="true" value="<?= $this -> attribute['id'];?>-<?= $value['id'];?>" name="<?= \S::seo( $attribute_details['language']['name'] );?>">
+          <input type="radio" id="<?= $this -> attribute['id'];?>-<?= $value['id'];?>" <? if ( $value['is_default'] ):?>checked="checked"<? endif;?> require="true" value="<?= $this -> attribute['id'];?>-<?= $value['id'];?>" name="<?= \Shared\Helpers\Helpers::seo( $attribute_details['language']['name'] );?>">
           <label for="<?= $this -> attribute['id'];?>-<?= $value['id'];?>" order="<?= $this -> order;?>"><?= \shop\ProductAttribute::get_value_name( $value['id'], $lang_id );?></label>
         </div>
         <? if ( $value['is_default'] ):?>