Show each subagent’s current task at a glance in the Codex CLI TUI

Feature request

When multiple subagents are running, the Codex CLI TUI should show the current task of each subagent at a glance, without requiring the user to open every subagent thread or inspect raw logs.

Today, a status such as working does not explain what the agent is actually doing. This makes it difficult to quickly understand task coverage, notice duplicated work, or decide whether intervention is needed.

Proposed UI

Add a compact, persistent or easily expandable subagent summary with one line per agent:

researcher   working   Inspecting authentication flow
reviewer     working   Checking tests for regressions
implementer  done      Updating token refresh handling

At minimum, each row should show:

• subagent name or ID
• current task
• lifecycle status

The task text should update when the subagent moves to a new phase. Detailed output can remain available through a drill-down view.

Why this is separate

#22099 proposes broader background-task and subagent management. This request is intentionally narrower: the current task of every active subagent should be immediately visible in the normal CLI workflow.