feat: rejected-cookie cache exclusions for WooCommerce cart

Add wp_recache_rejected_cookies option (defaults: woocommerce_items_in_cart,
wp_woocommerce_session_*, wp-postpass, comment_author_*, wordpress_*) that
bypasses page cache when any listed cookie is present. Both the WP-level
check (wp_recache_should_exclude) and the standalone drop-in apply the
same exact/prefix matching logic. Editing the option regenerates the
drop-in and purges all cache.

includes/Activator.php

@@ -48,6 +48,13 @@ class WP_Recache_Activator {
             'cache_enabled' => true,
             'separate_mobile_cache' => false,
             'exclude_urls' => ['/cart', '/checkout', '/my-account'],
+            'rejected_cookies' => [
+                'woocommerce_items_in_cart',
+                'wp_woocommerce_session_*',
+                'wp-postpass',
+                'comment_author_*',
+                'wordpress_*',
+            ],
             'minify_css' => false,
             'minify_js' => false,
             'lazyload_images' => false,
@@ -64,8 +71,20 @@ class WP_Recache_Activator {
     /**
      * Write the standalone cache server required by the advanced-cache.php
      * drop-in. Must run without WordPress loaded.
+     *
+     * Public so Admin can regenerate the drop-in when options change.
      */
-    private static function create_cache_server() {
+    public static function create_cache_server() {
+        $rejected_cookies = get_option('wp_recache_rejected_cookies', [
+            'woocommerce_items_in_cart',
+            'wp_woocommerce_session_*',
+            'wp-postpass',
+            'comment_author_*',
+            'wordpress_*',
+        ]);
+
+        $cookies_php = var_export($rejected_cookies, true);
+
         $content = '<?php
 /**
  * WP Recache early cache serving.
@@ -82,9 +101,25 @@ if (!empty($_SERVER[\'QUERY_STRING\'])) {
     return;
 }
 
-foreach ($_COOKIE as $name => $value) {
-    if (strpos($name, \'wordpress_logged_in\') === 0) {
-        return;
+$rejected_cookies = ' . $cookies_php . ';
+
+foreach ($rejected_cookies as $cookie) {
+    $cookie = trim($cookie);
+    if ($cookie === \'\') {
+        continue;
+    }
+
+    if (substr($cookie, -1) === \'*\') {
+        $prefix = substr($cookie, 0, -1);
+        foreach ($_COOKIE as $name => $value) {
+            if (strpos($name, $prefix) === 0) {
+                return;
+            }
+        }
+    } else {
+        if (isset($_COOKIE[$cookie])) {
+            return;
+        }
     }
 }