Function format_agent_rows 

pub fn format_agent_rows(
    agents: &[AgentStatusEntry],
    now: Instant,
) -> Vec<AgentRow>

Converts raw agent status entries into formatted display rows.

When an entry’s most-recent status message carries a phase, the row’s status field renders that phase (with the matching status symbol) instead of the message-type-derived label. Used by the supervisor row, where labels like "feedback" (the wire message type) are misleading and the real lifecycle phase is "watching", "merging", etc.

Pure function: performs no I/O, holds no locks, and is deterministic given the same inputs.