[BUG] Desktop app (Code tab): request_directory rejects mapped network drive that folder picker accepts; UNC paths never open in file pane

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet (related issues linked below cover neighbouring symptoms, not this one)
• [x] This is a single bug report
• [ ] I am using the latest version of Claude Code (desktop app bundles 2.1.295; latest on npm is 2.1.296)

What's Wrong?

In a local Code tab session of the Claude desktop app, a repository on an SMB share (\\server\share, persistently mapped as W:) cannot be added through request_directory with a path, although the native folder picker accepts the same mapped drive.

1. request_directory with a path fails with The requested directory could not be resolved. for \\server\share, W:\, W:\subfolder and a local directory symlink pointing to the share.
2. request_directory without a path (native folder picker) accepts W:\, after which the file pane opens W:\... files.
3. Even after W:\ is granted, \\server\share\... paths to the same files are rejected. Files edited through UNC paths cannot be opened from the "Edited N files" list.
4. A UNC entry in permissions.additionalDirectories is silently dropped from the session's working directories, and the picker grant is session-only (see related persistence issues below).

What Should Happen?

• Programmatic request_directory accepts the same mapped drive the picker accepts.
• UNC paths match a granted mapped drive pointing to the same share (or UNC can be granted directly).
• A way to persist the grant, e.g. honouring additionalDirectories.

Error Messages/Logs

request_directory with path \\server\share, W:\, W:\subfolder or symlink to share:
  The requested directory could not be resolved.
File pane for \\server\share\... after W:\ was granted:
  path could not be resolved inside this session's working directory or granted folders.
"Edited N files" entry for file edited via UNC path:
  Couldn't find this file - It can't be created from here.

Steps to Reproduce

1. Map an SMB share persistently: net use W: \\server\share /persistent:yes
2. Open a local Code tab session in the Claude desktop app with a local working folder (e.g. C:\project).
3. Ask Claude to call request_directory with path W:\ (or \\server\share): "The requested directory could not be resolved."
4. Ask Claude to call request_directory without a path and pick W:\ in the native picker: access is granted.
5. Open W:\some\file.php in the file pane: works. Open \\server\share\some\file.php: rejected.
6. Start a new session: the grant is gone (stored with "destination": "session").

Claude Model

Opus

Is this a regression?

I don't know

Claude Code Version

2.1.295 (Claude Code), Claude desktop app 2.31226.1.0 (Microsoft Store package)

Platform

Anthropic API

Operating System

Windows (Windows 10 22H2, build 19045)

Terminal/Shell

Other (Claude desktop app, Code tab)

Additional Information

Related:

• https://github.com/anthropics/claude-code/issues/45297 (Cowork rejects UNC folders)
• https://github.com/anthropics/claude-code/issues/91026 (same "could not be resolved" for virtual drives; mapped drive reported working there via picker)
• https://github.com/anthropics/claude-code/issues/100368 (mapped drive in Code tab, auto mode)
• https://github.com/anthropics/claude-code/issues/94446 (file viewer cannot open files under additionalDirectories)
• https://github.com/anthropics/claude-code/issues/93779 and https://github.com/anthropics/claude-code/issues/94678 (folder grants do not persist across sessions)