[BUG] Agents UI: status-rail text overlaps agent output pane at left edge

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the new agents feature (released ~2026-05-11), the agent output view appears to use a two-pane layout — a narrow status/summary rail on the left and the full agent output on the right. The two panes overlap at the left edge: truncated text from the rail renders on top of, or in the same column as, the first few characters of the agent's full output.

The fragments that bleed through look like the first 1–4 characters of lines from the agent's status summary (e.g. "St", "Th", "Ph", "Ho", "Ke", "Wh1.",
"Wh2.", "1.", "e"), and they obscure the first few characters of the actual output rendered in the main pane.

This only happens in the agents view. Normal Claude Code conversation output renders cleanly. See attached screenshot — Python pseudocode in an agent output pane, with rail fragments overlaying the leftmost column.

What Should Happen?

The status rail and the agent output pane should occupy distinct, non- overlapping regions. The first character of every line in the agent output
pane should be fully readable, with no overlay from the status rail.

Error Messages/Logs

Steps to Reproduce

1. Spawn one or more agents (e.g. via the Agent tool in a Claude Code session, or any subagent invocation that produces streaming output).
2. Open the agents view to inspect an agent's output.
3. While the agent is streaming, or after it finishes, scroll through its output pane.
4. Observe truncated 1–4 character fragments overlaid on the leftmost column of the main output. The fragments correspond to the starts of lines from the agent's status summary on the left rail.

Easier to reproduce when the agent output contains code blocks or content whose indentation differs from the status summary's text.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.139

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• Feature: new agents view, first seen on 2026-05-11.
• Terminal: Windows Terminal hosting PowerShell 7.6.0.
• Only the agents view is affected — main Claude Code output renders cleanly.
• Screenshot attached shows Python pseudocode in an agent output pane with rail fragments ("$V", "St", "Th", "de", "Ph", "Ho", "Ke", "Wh1.", "Wh2.",

"1.", "e") overlaying the leftmost column.