Module github_copilot 

GitHub Copilot API client for LLMG

Implements the Provider trait for GitHub Copilot Chat API using OAuth device flow.

Authentication Flow:

1. Get device code from GitHub
2. User visits verification URL and enters code
3. Poll for access token
4. Exchange access token for Copilot API key

Environment variables:

• GITHUB_COPILOT_ACCESS_TOKEN: Cached OAuth access token
• GITHUB_COPILOT_API_KEY: Cached Copilot API key
• GITHUB_COPILOT_TOKEN_DIR: Directory to store tokens (default: ~/.config/llmg/github_copilot)

Structs

GitHubCopilotClient

GitHub Copilot API client