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/advanced-features/advanced-features-static-classes.md

@@ -0,0 +1,27 @@
+Static Classes {#advanced.features.static.classes}
+==============
+
+You can directly access static classes. The syntax is the same as in
+PHP.
+
+> **Note**
+>
+> Direct access to PHP classes is not recommended. This ties the
+> underlying application code structure directly to the presentation,
+> and also complicates template syntax. It is recommended to register
+> plugins which insulate templates from PHP classes/objects. Use at your
+> own discretion. See the Best Practices section of the Smarty website.
+
+
+    {assign var=foo value=myclass::BAR}  <--- class constant BAR
+
+    {assign var=foo value=myclass::method()}  <--- method result
+
+    {assign var=foo value=myclass::method1()->method2}  <--- method chaining
+
+    {assign var=foo value=myclass::$bar}  <--- property bar of class myclass
+
+    {assign var=foo value=$bar::method}  <--- using Smarty variable bar as class name
+
+
+