Dev-Umgebung: Kompatibilität für PHP 8.3 + Smarty 4.5.6

- Smarty 4.1.1 → 4.5.6 (behebt dynamic property deprecations)
- Core-Klassen: #[\AllowDynamicProperties] für Admin_role, base, Config,
  Customer, Customer_group, CustomerGroups, Item, Structure, website
- website.class.php: counts[parent_id] initialisieren vor ++ (PHP 8.1)
- layout.class.php: HTTP_ACCEPT_LANGUAGE mit isset-Guard
- website_init.php: session_status()-Check vor session_start
- .htaccess: HTTPS-Redirect via X-Forwarded-Proto (statt SERVER_PORT)
- themes/easyshop_advanced/media/: Parent-Theme-Assets nachgezogen
- .gitignore: smarty.4.1.1.bak ausschließen

libs/smarty/docs/programmers/api-functions/api-register-resource.md

@@ -0,0 +1,46 @@
+registerResource()
+
+dynamically register resources
+
+Description
+===========
+
+void
+
+registerResource
+
+string
+
+name
+
+Smarty\_resource
+
+resource\_handler
+
+Use this to dynamically register a [Resource plugin](#resources) with
+Smarty. Pass in the `name` of the Resource and the object extending
+Smarty\_Resource. See [template resources](#resources) for more
+information on how to setup a function for fetching templates.
+
+> **Note**
+>
+> A resource name must be at least two characters in length. One
+> character resource names will be ignored and used as part of the file
+> path, such as `$smarty->display('c:/path/to/index.tpl');`
+
+> **Note**
+>
+> Prior to Smarty 3.1 `registerResource()` accepted an array of callback
+> functions. While this is still possible for backward compatibility
+> reasons, it is strongly discouraged as callback functions have been
+> deprecated as of Smarty 3.1.
+
+
+    <?php
+    $smarty->registerResource('mysql', new Smarty_Resource_Mysql());
+    ?>
+
+       
+
+See also [`unregisterResource()`](#api.unregister.resource) and the
+[template resources](#resources) section.