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/language-function-literal.md

@@ -0,0 +1,34 @@
+# {literal}
+
+`{literal}` tags allow a block of data to be taken literally. This is
+typically used around Javascript or stylesheet blocks where {curly
+braces} would interfere with the template
+[delimiter](../../programmers/api-variables/variable-left-delimiter.md) syntax. Anything within
+`{literal}{/literal}` tags is not interpreted, but displayed as-is. If
+you need template tags embedded in a `{literal}` block, consider using
+[`{ldelim}{rdelim}`](./language-function-ldelim.md) to escape the individual
+delimiters instead.
+
+> **Note**
+>
+> `{literal}{/literal}` tags are normally not necessary, as Smarty
+> ignores delimiters that are surrounded by whitespace. Be sure your
+> javascript and CSS curly braces are surrounded by whitespace. This is
+> new behavior to Smarty 3.
+
+```smarty
+<script>
+   // the following braces are ignored by Smarty
+   // since they are surrounded by whitespace
+   function myFoo {
+     alert('Foo!');
+   }
+   // this one will need literal escapement
+   {literal}
+     function myBar {alert('Bar!');}
+   {/literal}
+</script>
+```
+
+See also [`{ldelim} {rdelim}`](./language-function-ldelim.md) and the
+[escaping Smarty parsing](../language-basic-syntax/language-escaping.md) page.