Drain & delete nodes

Three node actions share one safe drain flow: drain and keep, drain and delete, or force delete. Every pod on the node is classified up front, then evicted in parallel with live per-pod progress.

• Up-front plan: evictable / DaemonSet / mirror static / terminating / emptyDir
• Evictions use the policy/v1 Eviction subresource - PodDisruptionBudgets are respected
• PDB blocks back off and retry, surfacing the exact budget message from the API
• A pod flips to Evicted only when it truly leaves the watch, not when the API ACKs
• Drain (Keep) ends with Uncordon or Leave Cordoned - for maintenance and rebalancing