[BUG] Cowork custom instructions reset to initial value on app restart

Description

Custom instructions set in Settings > Cowork (under the Cowork tab) do not persist across app restarts. They work during the active session but revert to the very first value ever saved when Claude Desktop is restarted or a new session is created.

Steps to reproduce

1. Open Claude Desktop > Cowork > Settings > Cowork
2. Write custom instructions in the text field and save
3. Verify they work in the current session
4. Quit and reopen Claude Desktop
5. Go back to Settings > Cowork — the instructions have reverted to the original first-ever saved value

What happens

The instructions revert to whatever was first written when the Cowork session was initially created. Subsequent edits (both from the UI and by directly editing the file) are lost on restart.

The underlying file is:

~/Library/Application Support/Claude/local-agent-mode-sessions/{org-id}/{user-id}/memory/CLAUDE.md

This file gets overwritten with the original value each time a new local session is created. Edits made via the UI or directly to this file are not persisted as the new source of truth.

Expected behavior

Custom instructions saved from the Cowork settings UI should persist across restarts and new sessions, or at minimum sync bidirectionally with the underlying file.

Environment

• Claude Desktop (macOS)
• Cowork mode, Cowork settings
• Observed consistently across multiple restarts