Support separate GitHub accounts for billing and API access

Feature summary

Support using different GitHub accounts for Copilot billing and GitHub API access.

What problem are you trying to solve?

When working with multiple GitHub accounts, the account used to pay for Copilot usage may differ from the account that has access to a repository. I want to use the intended billing account while performing GitHub API operations as a different account.

Proposed solution

• Allow the Copilot billing account to be selected independently from the account used for GitHub API calls.
• Allow selecting the API account per project/repository without changing the billing account.
• Clearly show which account is used for billing and which account is used for GitHub operations.

Workflow impact

This would support workflows involving separate work, personal, or organization-specific accounts, without requiring the repository-access account to also be the billing account.

Installation context

GitHub App with multiple GitHub accounts.

Start by reviewing the GitHub App's existing account, billing, and project or repository selection flows. Define how billing and API accounts are selected independently and how each is displayed; done means separate accounts work across the described multi-account workflow without changing the other account.