Cluster upgraded 1.31.5 -> 1.36.4 over 5 sequential minor hops (binary-swap per node, leader-last, Longhorn rebuild-freeze). Components: Cilium 1.16.5->1.20.1, Longhorn 1.7.3->1.12.1, GW-API CRDs ->v1.6.1, etcd 3.5->3.6. All validated; data intact. Co-Authored-By: Claude Opus 4.8 <[email protected]>