num_ctx parameter doesn't work with Ollama

### Issue

According to docs [https://cecli.dev/docs/llms/ollama/#ollama-setting-the-context-window-size](https://cecli.dev/docs/llms/ollama/#ollama-setting-the-context-window-size) this shoud work:
```yaml
- name: ollama_chat/qwen3.8:27b-gsq-rco
  extra_params:
    num_ctx: 57000
```
This works in aider but not in cecli.

### Version and model info

cecli 1.6.1