CVE-2025-1296: Nomad is vulnerable to unintentional exposure of the workload identity token and client secret token in audit logs

The vulnerability stems from three key points: 1) The ACL endpoint handler returned raw auth method data containing secrets via GetAuthMethod. 2) The event streaming system logged complete auth method data without filtering. 3) The ACLAuthMethod struct itself lacked inherent secret redaction. The commit fixes these by: 1) Adding Sanitize() calls in the API handler, 2) Adding sanitization in event generation, and 3) Implementing the Sanitize() method to scrub secrets. The high confidence for the first two comes from explicit pre-patch code showing missing sanitization, while the struct-level issue is medium confidence as it's an implicit design flaw.