fix(report): carry the admin note into the reporter result email

update_status() fired aksrt_report_status_changed without the note and
the mail listener hard-coded note => '', so the reply-to-reporter
comment written in the process form never reached the email. Pass the
sanitized note as a 4th action arg, render it via the existing {note}
placeholder, and map the raw status key to its Chinese label in the
email body. Contract test extended accordingly.

src/Messages/ReportCenter.php

@@ -140,10 +140,11 @@ class ReportCenter {
         ];
         $format = ['%s', '%s'];
 
-        if ($note !== '') {
+        $note_clean = $note !== '' ? sanitize_textarea_field($note) : '';
+        if ($note_clean !== '') {
             $notes = json_decode($existing->notes_json ?? '[]', true) ?? [];
             $notes[] = [
-                'note'      => sanitize_textarea_field($note),
+                'note'      => $note_clean,
                 'status'    => $new_status,
                 'operator'  => get_current_user_id(),
                 'timestamp' => current_time('mysql'),
@@ -154,7 +155,8 @@ class ReportCenter {
 
         $result = $wpdb->update($table, $update_data, ['id' => $report_id], $format, ['%d']);
         if ($result !== false) {
-            do_action('aksrt_report_status_changed', $report_id, (int) ($existing->reporter_id ?? 0), $new_status);
+            // 第 4 参携带处理说明：邮件通知（report_result）需要反馈给举报人。
+            do_action('aksrt_report_status_changed', $report_id, (int) ($existing->reporter_id ?? 0), $new_status, $note_clean);
         }
         return $result !== false;
     }