GitHub Copilot Agent (copilot-acp) remains stuck as not_ready in Berd

[YouSummoner]

Before filing

• I searched open and closed issues for duplicates.
• I reproduced this on the latest release.
• This is one bug, not several bundled together.

Closest existing issue

none found

What's broken

GitHub Copilot Agent not working.

Steps to reproduce

1. Launch Berd (v0.6.2) on macOS.
2. Go to Settings → AI providers / Agent harnesses.
3. Under Copilot ("GitHub Copilot coding agent", Installed via Homebrew · v1.0.80), click Sign in.
4. The browser opens to the GitHub OAuth authorization page (https://github.com/login/oauth/authorize?...).
5. Complete the sign-in / authorization flow in the browser.
6. The app log reports:

   [agent-setup copilot-acp Auth] Signed in successfully as <user>.
   [agent-setup copilot-acp Auth] fix succeeded
   

7. Return to the Berd Settings screen and click Refresh.

What you expected to happen

After completing OAuth sign-in and seeing fix succeeded, the Copilot entry should update to reflect a connected/authenticated state (replacing the "Sign in" button with a signed-in state/indicator), and allow creating sessions using the Copilot harness.

What actually happened

The Settings UI remains completely stuck on the initial state:

• The Sign in button remains visible under Copilot (Installed via Homebrew · v1.0.80).
• Clicking Refresh does not update the UI or reflect the authenticated status.
• Checking via berdctl info harnesses still returns "status": "not_ready".
• Attempting to start a session with the Copilot harness fails with:
  harness_not_ready: Agent harness "copilot-acp" is not ready (sign-in or setup required).

How often does it happen?

Every time — reliably reproducible

Berd version

0.6.2

Operating system

macOS (Apple Silicon)

Model and provider

Github Copilot

Relevant log output

[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] starting fix
[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] $ copilot login
[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] Opening your browser to authenticate...
[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] Waiting for authorization...
[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] Signed in successfully as <username>.
[berd_lib::commands::agent_setup][INFO] [agent-setup copilot-acp Auth] fix succeeded

Screenshots, recordings, or other context

No response