Fix SanTrustDomainError

✅ Solution

The "SanTrustDomainError" in Istio usually occurs when the trust domain aliases are not properly configured or propagated across clusters, leading to misidentification of service identities. To fix, ensure that the `trustDomainAliases` field in the Istio MeshConfig is correctly set in each cluster, reflecting all trust domains involved in multicluster communication; then verify that istiod has successfully propagated this configuration to all relevant components, including ztunnel in ambient mesh.