Support GitHub's organization custom instructions

[digitarald]

Support https://docs.github.com/en/enterprise-cloud@latest/copilot/how-tos/configure-custom-instructions/add-organization-instructions in VS Code.

CCA also just added support: https://github.blog/changelog/2025-11-05-copilot-coding-agent-supports-organization-custom-instructions/ .

Scope:

• Automatic inclusion when instructions are set for the current repo
• Show {Org} instructions in references
• Log details about the applied org instructions for debugging

[jeremytbrun]

I'd love to see this as well, but much like #274341 we need it to work even if the working repository is hosted outside of GitHub. As an organization we host our repos in Azure DevOps, but we license our developers with GitHub Copilot under a GitHub Enterprise account.

[im-aIex]

same here. as a workaround my organization had a separate repository that we pointed to within our individual repos (outlined in #273817 (comment)), but it seems a recent update has made it so copilot cannot natively read instructions outside the workspace.

this is important for organizations to get their code standards baked into copilot out of the box.