Can't find OpenAI or Anthropic Models

**Describe the bug**
There are no OpenAI or Anthropic models to select after putting in a valid API key. This may be related to #2626 because I have not gotten the ACP for Claude or Codex to install.

**Steps to reproduce**
1. If I skip the ACP installation and go straight to configuring the model settings.
2. I select Buzz or Goose as default harness and then select OpenaAI/ANthropic for provider
3. paste in a valid api key for the selected provider
4. no models populate the model selection box.

**Expected behavior**
I expected models to populate so that I could select one and then select the effort for that model.

**Version and platform**
Find your version at the bottom of the Settings sidebar. Write "unknown" if you can't determine it.
- Buzz version: 0.5.1
- OS: Windows 11 PRO

**Logs / additional context**
Paste any relevant logs, error messages, or screenshots here.