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-clear-assign.md

@@ -0,0 +1,32 @@
+clearAssign()
+
+clears the value of an assigned variable
+
+Description
+===========
+
+void
+
+clearAssign
+
+mixed
+
+var
+
+This can be a single value, or an array of values.
+
+
+    <?php
+    // clear a single variable
+    $smarty->clearAssign('Name');
+
+    // clears multiple variables
+    $smarty->clearAssign(array('Name', 'Address', 'Zip'));
+    ?>
+
+       
+
+See also [`clearAllAssign()`](#api.clear.all.assign),
+[`clearConfig()`](#api.clear.config),
+[`getTemplateVars()`](#api.get.template.vars), [`assign()`](#api.assign)
+and [`append()`](#api.append)