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/designers/language-builtin-functions/index.md

@@ -0,0 +1,35 @@
+# Built-in Functions
+
+Smarty comes with several built-in functions. These built-in functions
+are the integral part of the smarty template engine. They are compiled
+into corresponding inline PHP code for maximum performance.
+
+You cannot create your own [custom functions](../language-custom-functions/index.md) with the same name; and you
+should not need to modify the built-in functions.
+
+A few of these functions have an `assign` attribute which collects the
+result the function to a named template variable instead of being
+output; much like the [`{assign}`](language-function-assign.md) function.
+
+- [{append}](language-function-append.md)
+- [{assign} or {$var=...}](language-function-assign.md)
+- [{block}](language-function-block.md)
+- [{call}](language-function-call.md)
+- [{capture}](language-function-capture.md)
+- [{config_load}](language-function-config-load.md)
+- [{debug}](language-function-debug.md)
+- [{extends}](language-function-extends.md)
+- [{for}](language-function-for.md)
+- [{foreach}, {foreachelse}](language-function-foreach.md)
+- [{function}](language-function-function.md)
+- [{if}, {elseif}, {else}](language-function-if.md)
+- [{include}](language-function-include.md)
+- [{insert}](language-function-insert.md)
+- [{ldelim}, {rdelim}](language-function-ldelim.md)
+- [{literal}](language-function-literal.md)
+- [{nocache}](language-function-nocache.md)
+- [{section}, {sectionelse}](language-function-section.md)
+- [{setfilter}](language-function-setfilter.md)
+- [{strip}](language-function-strip.md)
+- [{while}](language-function-while.md)
+