Function current_column 

pub(crate) fn current_column(host: &HostStatusEntry) -> String

CURRENT-column rendering with a context-aware fallback chain. The agent’s post-activation closure observation (current_closure_hash) is the canonical value, but it’s None between rollout-open and ActivationCompleted (the switch-in-progress window). During that window the host is demonstrably executing pending_closure_hash — the closure the agent reported running when it acked the dispatch — and the operator wants to see it.

Fallback order:

1. current_closure_hash — post-activation observed closure.
2. pending_closure_hash rendered with a trailing arrow — mid-rollout: agent has acked, switch in progress, host still on this closure.
3. <unseen> — no closure observation. The STATUS column already conveys in-flight state via its → in progress / → activating labels; CURRENT staying <unseen> is honest about the lack of closure data.