fix: copilot model not show in /model when copilot provider fallback to gh auth token

[Marvae]

What changed and why

Fixes #9768

/model (the model picker) calls list_authenticated_providers() to discover which providers have valid credentials. It checks:

1. Environment variables (COPILOT_GITHUB_TOKEN, GH_TOKEN, GITHUB_TOKEN)
2. Hermes auth store (~/.hermes/auth.json)
3. OAuth credential pool

However, many copilot users authenticate solely through the GitHub CLI (gh auth token). These tokens are resolved dynamically by resolve_copilot_token() in copilot_auth.py and don't exist in any of the three stores above. As a result, copilot does not appear in the /model provider list even when the user is actively using it as their provider.

This affects all /model entry points — CLI (cli.py) and Gateway messaging platforms (gateway/run.py) — since they all call the same list_authenticated_providers() function.

Fix

Seed copilot credentials from resolve_copilot_token() in the credential pool's _seed_from_singletons() (agent/credential_pool.py), alongside the existing anthropic and openai-codex seeding logic. This is the correct architectural layer — the credential pool already handles dynamic credential discovery for other providers — rather than adding a one-off fallback in list_authenticated_providers().

How to test

1. Ensure no copilot env vars are set: unset COPILOT_GITHUB_TOKEN GH_TOKEN GITHUB_TOKEN
2. Ensure gh auth token returns a valid token
3. Set provider: copilot in ~/.hermes/config.yaml
4. Run hermes and type /model
5. Before fix: copilot does not appear in the provider list
6. After fix: copilot appears with its models

Screenshots

Before

After

Automated tests

pytest tests/agent/test_credential_pool.py::test_load_pool_seeds_copilot_via_gh_auth_token tests/agent/test_credential_pool.py::test_load_pool_does_not_seed_copilot_when_no_token -v

Two new tests in tests/agent/test_credential_pool.py:

• test_load_pool_seeds_copilot_via_gh_auth_token — copilot credentials seeded into pool when resolve_copilot_token() succeeds
• test_load_pool_does_not_seed_copilot_when_no_token — pool stays empty when no token available

Platform tested

• macOS (Apple Silicon)

[teknium1]

Merged via PR #9810. Your copilot seeding commit was cherry-picked onto current main with your authorship preserved in git log. We also added qwen-oauth seeding for the same gap pattern you identified. Thanks for the clean fix, @Marvae!