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-variables/variable-compile-id.md

@@ -0,0 +1,44 @@
+\$compile\_id {#variable.compile.id}
+=============
+
+Persistent compile identifier. As an alternative to passing the same
+`$compile_id` to each and every function call, you can set this
+`$compile_id` and it will be used implicitly thereafter.
+
+If you use the same template with different [pre- and/or
+post-filters](#plugins.prefilters.postfilters) you must use a unique
+`$compile_id` to keep the compiled template files separated.
+
+For example a [prefilter](#plugins.prefilters.postfilters) that
+localizes your templates (that is: translates language dependent parts)
+at compile time, then you could use the current language as
+`$compile_id` and you will get a set of compiled templates for each
+language you use.
+
+
+    <?php
+    $smarty->compile_id = 'en';
+    ?>
+
+      
+
+Another application would be to use the same compile directory across
+multiple domains / multiple virtual hosts.
+
+
+    <?php
+
+    $smarty->compile_id = $_SERVER['SERVER_NAME'];
+    $smarty->compile_dir = '/path/to/shared_compile_dir';
+
+    ?>
+
+      
+
+> **Note**
+>
+> In Smarty 3 a `$compile_id` is no longer required to keep templates
+> with same name in different [`$template_dir`
+> folders](#variable.template.dir) separated. The [`$template_dir` file
+> path](#variable.template.dir) is encoded in the file name of compiled
+> and cached template files.