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/resources/resources-streams.md

@@ -0,0 +1,27 @@
+Stream Template Resources {#resources.streams}
+=========================
+
+Streams allow you to use PHP streams as a template resource. The syntax
+is much the same a traditional template resource names.
+
+Smarty will first look for a registered template resource. If nothing is
+found, it will check if a PHP stream is available. If a stream is
+available, Smarty will use it to fetch the template.
+
+> **Note**
+>
+> You can further define allowed streams with security enabled.
+
+Using a PHP stream for a template resource from the display() function.
+
+     
+     $smarty->display('foo:bar.tpl');
+     
+       
+
+Using a PHP stream for a template resource from within a template.
+
+     
+     {include file="foo:bar.tpl"}
+     
+