#-mentions is broken in copilot chat

[conradkoh]

• Copilot Chat Extension Version: I can't see this
• VS Code Version: 1.102.1
• OS Version: Sequoia 15.5
• Feature (e.g. agent/edit/ask mode): agent
• Selected model (e.g. GPT 4.1, Claude 3.7 Sonnet): GPT 4.1
• Logs: -

Steps to Reproduce:

1. type # and put "test" as a search query and see that it works
2. backspace a single letter to search and see that all results disappear
3. any subsequent search stops working for search starting with that letter
4. try searching for another letter and it seems to work

Expected behavior

• This should work exactly like how Cmd + P works when searching files
• This should work by specifying the folders then the files as well (e.g. the query "tepa" should result in "/apps/webapp/app/test/page.tsx" to show