copilot: connected OAuth provider syncs no models — silent failure, models never become available #58219

Summary

After completing the GitHub Copilot device-flow login in the TUI, the stored credential is valid (the Copilot API returns the user's model list), but OpenCode never exposes any github-copilot/* model: GET /api/model keeps returning only opencode/* models, and selecting any Copilot model fails with Model unavailable. No sync error is logged.

Environment

• opencode version: v2.1.3
• OS: Linux 6.18.54.1-microsoft-standard-WSL2 (x86_64, WSL2)
• Terminal: xterm-256color (TERM_PROGRAM unset)
• Shell: /bin/bash
• Install/channel: latest
• Active plugins: none found in config

Reproduction

1. Run /connect in the TUI, choose GitHub Copilot → Login with GitHub Copilot → GitHub.com, complete the device flow in the browser. Server logs the credential as created (integrationID github-copilot, type oauth, active true).
2. opencode auth list shows GitHub Copilot stored.
3. opencode models lists only the 9 opencode/* free models; no github-copilot/* entries appear.
4. Run any Copilot model: opencode run --model github-copilot/gpt-5-mini "hi" → immediate Error: Model unavailable: github-copilot/gpt-5-mini (server logs SessionRunnerModel.ModelUnavailableError).
5. GET /api/provider shows github-copilot with activation: "auto" (before config) — setting an explicit providers: {"github-copilot": {}} in ~/.config/opencode/opencode.json and calling opencode reload flips activation to enabled, but no models appear.
6. Force a service restart: same result.

Expected Behavior

The CLI docs state OpenCode "fetches the account's current model list after login and whenever the active Copilot account changes" and that a failed sync is logged as failed to sync GitHub Copilot models. Expected: github-copilot models from the account become selectable in /models and via opencode run --model github-copilot/<id>.

Actual Behavior

No Copilot model ever becomes available in any client (TUI, opencode run, GET /api/model), both via the shared background service and --standalone mode. Notably, no failed to sync GitHub Copilot models warning is logged — the sync attempt appears to be silently skipped or swallowed.

Additional Context

Evidence that the account and token are valid (i.e., not an entitlement problem):

• Directly calling Copilot's API with the stored OAuth token returns 48 models:
  GET https://api.individual.githubcopilot.com/models with Authorization: Bearer <stored token> → HTTP 200, 48 model entries.
• The cached models.dev catalog in the background service (kv key models-dev:catalog) contains github-copilot with 36 models.
• The integration endpoint reports a live connection: GET /api/integration/github-copilot → connections: [{type: credential, active}].
• GET /api/provider/github-copilot shows the provider without any account-resolved models.

Completely reproducible across: shared service restart, opencode reload, opencode auth switch <integration> <label>, explicit provider activation in config, and a fresh --standalone server. Workarounds tried (none made models appear): config activation, auth switch, service restart, standalone mode.