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-config.md

@@ -0,0 +1,35 @@
+clearConfig()
+
+clears assigned config variables
+
+Description
+===========
+
+void
+
+clearConfig
+
+string
+
+var
+
+This clears all assigned [config variables](#language.config.variables).
+If a variable name is supplied, only that variable is cleared.
+
+
+    <?php
+    // clear all assigned config variables.
+    $smarty->clearConfig();
+
+    // clear one variable
+    $smarty->clearConfig('foobar');
+    ?>
+
+       
+
+See also [`getConfigVars()`](#api.get.config.vars),
+[`config variables`](#language.config.variables),
+[`config files`](#config.files),
+[`{config_load}`](#language.function.config.load),
+[`configLoad()`](#api.config.load) and
+[`clearAssign()`](#api.clear.assign).