Windows desktop + WSL: creating a project fails with AbsolutePathBuf deserialized without a base path

Environment

• Windows desktop app package: OpenAI.Codex_26.908.9136.0_x64
• Bundled WSL agent: codex-cli 0.154.0-alpha.6.2
• Agent environment: WSL2 (Ubuntu 22.04)
• Project folder on a Windows drive, accessible from WSL through /mnt/<drive>/...

Reproduction

1. Use the Windows desktop app with the agent running in WSL.
2. Select Create project, enter a name and submit without selecting a source folder.
3. Alternatively, add an existing Windows folder as the source and submit.

Both routes show Failed to create project. Restarting the app does not fix creation of subsequent projects.

Expected

Create the project and display it in the sidebar, converting source paths into the execution host's path format where required.

Actual / evidence

• The no-source-folder flow creates the directory and initializes .git, but project registration fails.
• Retrying creates additional numbered directories without registering the project.
• Startup logs also show [host-app-server-projects] Local app-server assignment sync failed with Invalid request: AbsolutePathBuf deserialized without a base path.
• A diagnostic request to the bundled Linux app-server reproduces that exact error when project/import receives a Windows-style root such as F:\\Projects\\Example.
• project/create / project/import succeed when the same location is supplied as /mnt/f/Projects/Example.
• The installed desktop project backend passes rootPaths directly as roots: [{path: ...}] for project create/import. This suggests native Windows paths are reaching the Linux path parser without translation.

There also appears to be a migration issue when changing execution environments: the desktop's project-ID mappings are keyed by the native versus WSL Codex home identity, while each environment can use a different SQLite location. Existing project mappings must resolve against the active backend.

Impact

Basic project creation is blocked, the UI exposes only a generic error, and retries leave duplicate folders. Please handle host path conversion for both create and import and surface the underlying error without leaving orphaned folders.

This report intentionally excludes personal paths, screenshots, conversation contents, and credentials.

Start at the project/create and project/import handling where rootPaths become roots, then trace host-app-server-projects assignment sync and the desktop project-ID mappings across native and WSL Codex homes. Verify Windows paths are converted for the active backend, mappings resolve against its SQLite location, errors are surfaced, and failed creation does not leave orphaned folders.