Chat show "No Active Xcode Workspace"

**Describe the bug**
When I’m using Xcode, my dialog box remains unresponsive.I tried uninstalling and reinstalling, but the result is still the same.What should I do to fix it?

**Versions**
- Copilot for Xcode: [Version 0.33.0 (0.33.0)]
- Xcode: [Version 16.0 (16A242d)]
- macOS: [15.0 (24A335)]

**Steps to reproduce**
1. open Xcode and open Chat
2. write some code

**Screenshots**

**Logs**

**Additional context**

Start by reproducing the unresponsive Chat dialog in Xcode 16 on macOS 15 using the reported steps. Review the Chat flow and the attached screenshot, then collect the relevant logs from ~/Library/Logs/GitHubCopilot/; done means identifying the cause of the “No Active Xcode Workspace” state and confirming that Chat responds when working in an open workspace.

Written by the indexing model from the issue text.