[Bug] Cloud sessions and Remote control both fail - app does not pass GitHub ...

The issue is in the credential handoff between the GitHub Copilot app and its bundled CLI. Start by examining the app's session creation and remote control enablement code paths, focusing on how the GitHub token is passed to the CLI. Look at the CLI logs for 'GitHub token provider registration' errors. The fix likely involves the app's token provider mechanism. 'Done' means cloud sessions and remote control work from the app.

[Bug] Cloud sessions and Remote control both fail - app does not pass GitHub token to CLI

ENVIRONMENT

• GitHub Copilot app 1.1.23 (d1a29ed), macOS arm64, bundled CLI 1.0.87-0
• Also reproduced on app 1.1.22 / CLI 1.0.84-5. Remote control failing since app 1.1.20 (2026-09-19)
• github.com account, Copilot Business, single account signed in
• Entitlements OK: cli_remote_control_enabled=true, cloud_session_storage_enabled=true, copilot_app_enabled=true

SYMPTOMS

1. Cloud session creation always fails immediately:
   "RPC error -32601: Unhandled method session.create"
2. Enabling Remote control on a local session always fails:
   "RPC error -32603: Request session.remote.enable failed with message: Failed to set up remote session. Ensure the working directory is a GitHub repository and you are authenticated."
   Local (non-cloud, non-remote) sessions work fine with the same CLI.

REPRO

• Project with github.com HTTPS remote -> New session with execution location = Cloud -> fails ~0.3s after CLI spawn
• Any local session -> toggle Remote control -> fails

KEY LOG LINES
App log:
creating new session ... account_scope=Workspace(...) remote_enabled=true execution_location=Cloud
session creation failed error=RPC error -32601: Unhandled method session.create
CLI process log (spawned by app):
[managedSettings] server policy fetch skipped: no authenticated GitHub host available
[remote::shared_api] No authentication token available; remote export disabled
[remote::api_session_exporter] remote session batch flush failed: GitHub credential authority error: GitHub token provider registration "" is unavailable
[mcp::client] dynamic header provider failed: GitHub token provider registration "" is unavailable

WHAT I CHECKED

• gh auth OK (scopes: repo, workflow, read:org, ...)
• App accounts entry OK; token refreshed after re-login
• No GH_TOKEN / GITHUB_TOKEN / COPILOT_* overrides in shell or launchctl
• Single app instance running
• Sign out -> sign in -> full restart (Cmd+Q): STILL FAILS
• Standalone CLI 1.0.87-0 run outside the app ("copilot --remote" in a TTY, same account token): WORKS ("Remote session access enabled")

CONCLUSION
Account, entitlements, token and CLI binary are fine. The app -> CLI credential handoff seems broken (token provider registration passed to CLI is "unavailable"), breaking both Remote control and Cloud session creation.

Timestamps (UTC) for log lookup: remote control failures 2026-09-23 21:10, cloud failures 21:17 and 21:25 (after re-login). Full logs available on request.