Remote session UI: plan-mode plan file chip fails to open ("file is on the machine running this remote session") because it lives outside the working directory

Environment

• Claude Code version: 2.1.226
• OS: Windows 11 Pro (10.0.26200)
• Access: driving the session remotely from the claude.ai UI (remote control session to my machine)

Bug

In plan mode, the harness instructs Claude to write the plan file to C:\Users\<user>\.claude\plans\<slug>.md (a path assigned by Claude Code itself, outside the project working directory).

The chat renders a clickable file chip for that Write (e.g. Creado <plan-slug>.md +35 -0), but clicking it fails with:

No se puede leer este archivo Este archivo se encuentra en la máquina que ejecuta esta sesión de control remoto y no se pudo cargar desde aquí. Es posible que esté fuera del directorio de trabajo de la sesión, o que haya sido movido o eliminado. C:\Users\<user>\.claude\plans\<plan-slug>.md

The file does exist on disk on the machine running the session — it was just written by the Write tool seconds earlier.

Expected

Since the plan file path is chosen by Claude Code's own plan-mode workflow, the remote file viewer should be able to fetch and display it even though it lives outside the session's working directory (or the plan file should be placed somewhere the viewer can read).

Steps to reproduce

1. Connect to a Claude Code session on another machine from the claude.ai UI (remote control).
2. Enter plan mode and let Claude write the plan file to the harness-assigned path under ~/.claude/plans/.
3. Click the file chip shown in the chat for that Write.
4. Error panel appears instead of the file contents.

Notes

• Reading/editing files inside the project working directory works fine from the same remote session; only the out-of-workspace plan file fails.