[Bug] Hermes ACP initializes but every managed prompt hangs until 60s timeout on Windows

## Describe the bug

A Buzz Desktop managed Hermes ACP agent initializes successfully, but every incoming prompt hangs until `buzz-acp` reports a 60-second request timeout.

This happens even for a one-word prompt and is not caused by worker execution, Kanban, or a long model response.

## Steps to reproduce

1. Run Buzz Desktop 0.5.3 on Windows 10 AMD64.
2. Configure a managed Hermes Agent ACP runtime using Hermes Agent 0.19.1.
3. Configure an explicit model ID: `gpt-5.6-sol`.
4. Send a simple prompt such as `Hi`.
5. Wait for the response.

## Expected behavior

The agent should return a short response within a few seconds.

## Actual behavior

The message is accepted by Buzz, but no assistant response appears. After approximately 60 seconds, Buzz logs:

```text
Request timeout — agent did not respond within 60s
```

Buzz then requeues the failed batch and respawns the Hermes ACP process.

## Evidence

Buzz's harness log shows that:

- ACP initialization succeeds.
- Hermes creates the OpenAI Codex client successfully.
- The configured model is `gpt-5.6-sol`.
- MCP tools register successfully.
- No model response or tool event appears before the timeout.

Sanitized log excerpts:

```text
buzz-acp: agent initialized
configured_model=gpt-5.6-sol
OpenAI client created provider=openai-codex model=gpt-5.6-sol
MCP: registered 7 tool(s) from 1 server(s)
Request timeout — agent did not respond within 60s
```

The same minimal prompt succeeds immediately when run directly through Hermes CLI:

```text
MANAGER_OK
```

This isolates the failure to the Buzz ACP request/response path rather than Hermes, model authentication, or the model endpoint.

The Buzz startup log also reports:

```text
permission_mode=bypassPermissions
```

Please confirm whether Buzz sends a `session/set_config_option` permission-mode request to Hermes ACP. If Hermes does not support that configuration vocabulary, the error may be waiting indefinitely instead of being returned as a handled ACP error.

## Environment

- Buzz Desktop: 0.5.3
- OS: Windows 10 AMD64
- Hermes Agent: 0.19.1
- ACP model: `gpt-5.6-sol`
- Harness: managed Hermes Agent ACP
- Direct Hermes CLI: same machine and credentials, succeeds

## Related issues

- #3729 — buzz-acp permission-mode values can cause ACP initialization hangs
- #3934 — Hermes model discovery through `models.availableModels`
- #3768 — Hermes managed-session provisioning

No credentials, private channel IDs, identity IDs, API keys, or Hindsight data are included.