Assistant: Copilot completions support in ipynb files

[wurucheng123]

System details:

Positron and OS details:

版本: Positron Version: 2025.07.0 (Universal) build 74
Code - OSS Version: 1.100.0
Commit: fe621e8
Date: 2025-06-09T03:37:56.615Z
認可: 34.5.1
日期: 132.0.6834.210
Electron: 20.19.0
ElectronBuildId: 13.2.152.41-electron.0
Chromium: Darwin arm64 22.4.0
Node.js: undefined
V8: undefined
OS: undefined

Interpreter details:

Python 3.13.2

Describe the issue:

In ipynb files, github copilot can't perform autocompletion.

Steps to reproduce the issue:

1.create a file named test.ipynb
2.add a cell of python code
3.enter if __name__, github copilot does not suggest the following completion.

Expected or desired behavior:

enter if __name__, suggests == '__main__':

Were there any error messages in the UI, Output panel, or Developer Tools console?

[testlabauto]

Thank you for your feature request, @wurucheng123 !

I will move this to triage for prioritization.

[testlabauto]

This does appear to work in VSCode.

[sharon-wang]

Some initial investigation in #8498.