Exclude amzn.to links from broken link detection

Amazon short links (amzn.to) frequently time out or return misleading
status codes, producing false positives in the link health checker.
Skip these links entirely in check_single_link() by returning 'ok'
immediately when the host is amzn.to.

https://claude.ai/code/session_0114nzYukNFeahGbWczuMMpV

Author: claude

includes/class-rtg-link-checker.php

@@ -192,6 +192,18 @@ public static function save_results( $total, $broken ) {
      * @return array {status, reason, http_code}
      */
     public static function check_single_link( $url ) {
+        // Amazon short links (amzn.to) are excluded from broken link
+        // detection — they frequently time out or return misleading
+        // status codes, producing false positives.
+        $parsed_host = wp_parse_url( $url, PHP_URL_HOST );
+        if ( $parsed_host && 'amzn.to' === strtolower( $parsed_host ) ) {
+            return array(
+                'status'    => 'ok',
+                'reason'    => '',
+                'http_code' => 0,
+            );
+        }
+
         // Use GET instead of HEAD because many affiliate networks
         // (CJ, ShareASale, etc.) only redirect GET requests.
         $response = wp_remote_get( $url, array(