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-append.md

@@ -0,0 +1,61 @@
+append()
+
+append an element to an assigned array
+
+Description
+===========
+
+void
+
+append
+
+mixed
+
+var
+
+void
+
+append
+
+string
+
+varname
+
+mixed
+
+var
+
+bool
+
+merge
+
+If you append to a string value, it is converted to an array value and
+then appended to. You can explicitly pass name/value pairs, or
+associative arrays containing the name/value pairs. If you pass the
+optional third parameter of TRUE, the value will be merged with the
+current array instead of appended.
+
+NOTE.PARAMETER.MERGE
+
+
+    <?php
+    // This is effectively the same as assign()
+    $smarty->append('foo', 'Fred');
+    // After this line, foo will now be seen as an array in the template
+    $smarty->append('foo', 'Albert');
+
+    $array = array(1 => 'one', 2 => 'two');
+    $smarty->append('X', $array);
+    $array2 = array(3 => 'three', 4 => 'four');
+    // The following line will add a second element to the X array
+    $smarty->append('X', $array2);
+
+    // passing an associative array
+    $smarty->append(array('city' => 'Lincoln', 'state' => 'Nebraska'));
+    ?>
+
+       
+
+See also [`appendByRef()`](#api.append.by.ref),
+[`assign()`](#api.assign) and
+[`getTemplateVars()`](#api.get.template.vars)