Workspace working directory not updated after moving project to new location

[lgcenen]

Description

When a project is moved from its original location to a new path (e.g., an external drive), closing the old workspace in opencode GUI and re-adding it at the new path does not update the working directory. The environment still uses the original workspace path, which no longer exists.

Steps to Reproduce

1. Open a project at location A
2. Move/copy the project to location B
3. In opencode GUI, close the workspace and add location B
4. Start a session
5. Try to use any file system tool

Expected Behavior

The working directory should reflect the current workspace path (location B).

Actual Behavior

The environment still uses the original path (location A), causing file system tools to fail with NotFound: FileSystem.access errors.

Environment

• macOS
• opencode GUI

Notes

• The workspace path is stored in the GUI's data file, but even after updating it, the working directory is fixed at process launch time.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Desktop GUI reopens an existing session with the wrong workspace path after selecting a different project directory #29714: Desktop GUI reopens an existing session with the wrong workspace path after selecting a different project directory — similar symptom of the GUI using the wrong directory path
• opencode web on Windows resolves working directory to drive root instead of CWD #26966: opencode web on Windows resolves working directory to drive root instead of CWD — similar issue where the GUI/web mode picks up the wrong working directory

If your issue is distinct (specifically around macOS external drives mounted at /Volumes/), it would be helpful to cross-reference these issues.

[lgcenen]

Fixed in #30007