[Bug]: Google Vertex AI provider models not appearing in Models dashboard or /v1/models #202

provider: google-vertex
adapter: google
base_url: https://aiplatform.googleapis.com
auth_mode: key

3. Configure a Gemini model:
defaultModel: gemini-2.5-pro

4. Run model sync:
ocx sync

5. Verify the provider is detected:
ocx models

Expected:
google-vertex: gemini-2.5-pro
This appears correctly.

6. Open:
http://127.0.0.1:10100/#models
or check:
curl http://127.0.0.1:10100/v1/models
Expected:
google-vertex/gemini-2.5-pro
Actual:
No google-vertex Gemini models appear.
Only other providers/models are listed.

### Logs and screenshots

```shell
Relevant output:

### ocx models
google-vertex: gemini-2.5-pro *
The provider is detected.

### /v1/models


curl http://127.0.0.1:10100/v1/models | jq '.data[].id'

Output does not contain:
google-vertex/gemini-2.5-pro

but contains other providers such as:
google-antigravity/*
openrouter/*
xai/*
kimi/*

API config
curl http://127.0.0.1:10100/api/config

shows:
"google-vertex": {
  "defaultModel": "gemini-2.5-pro"
}

Provider integration
---

## Version *
0.145.0-alpha.18

OS *
macOS 26.5.1 (Apple Silicon)

Config shape *
providers:
  google-vertex:
    adapter: google
    base_url: https://aiplatform.googleapis.com
    auth_mode: key
    defaultModel: gemini-2.5-pro
API keys and credentials removed.