My extension implements vscode.FileSystemProvider. When the setting chat.useNestedAgentsMdFiles is enabled, the function promptsService.findAgentMDsInWorkspace never returns. As a result, GitHub Copilot Chat becomes unresponsive.

Repro steps:

1. start fsprovider-sample in vscode extension samples
2. use setup workspace command
3. enable Use Nested Agents Md Files setting
4. type any text in github copilot chat, click Send, no response.

Expected behaviors:
Copilot Chat should respond normally.

Version: 1.109.0-insider (user setup)
Commit: 03f79ac
Date: 2026-01-16T05:02:37.001Z
Electron: 39.2.7
ElectronBuildId: 13098910
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200