Add possibility to use glob patterns while calling /file in assistant

[mspanc]

Use case:

I have a C++ project using CMake with many nested subprojects. I'd like to use assistant to improve build config. Given that I'd like to add as a context all CMakeLists.txt in the project (but not other files). Now I have to add them manually, one by one:

That would be great if I can just type a glob pattern such as **/CMakeLists.txt and add them all at once.