[BUG] Cowork Windows: project-level folder not mounted in new conversations - only surfaces when file access is attempted

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?

A folder connected to a Cowork project weeks ago is not being mounted when new conversations are started within that project. The issue is silent, it only surfaces when Claude actually attempts to access a file. Conversations that rely only on memory and search complete normally without any error. The folder path is unchanged; it is a locally-synced Dropbox path (data on the laptop, not a network path).

Related Issues

#50168 (Windows: adding folder to existing session fails silently)
#40300 (Windows: folder permission not persisting after path edit)

What Should Happen?

A folder connected to a Cowork project should automatically be available in all new conversations opened within that project, without requiring the user to reconnect it each time.

Error Messages/Logs

Thought process
The user says "test folder connection" - this seems like they want to test whether a folder is connected to the session. Let me check if there's a connected folder/directory available.

Looking at the system context, it says "No user folders are connected yet. To work with the user's files, request a folder with mcp__cowork__request_cowork_directory."

So no folder is currently connected. I should let the user know this and offer to request a folder connection.

Done
No folder is currently connected to this session. To connect one, I can send a request — would you like me to do that now?

Steps to Reproduce

1) Create a Cowork project and connect a local folder
2) Have at least one conversation in the project
3) Start a new conversation in the same project
4) Observe: Claude reports the folder is not connected, the system prompt confirms no user folder is mounted

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.177

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Issue predates the latest update. App was relaunched to apply the update and the problem persisted - confirming this is not a regression tied to a specific version.