Effort level resets on close

### Describe the bug

If I change the effort level from `medium` to `high` during model selection (Claude Sonnet 4.6, for example), it will not be saved when the CLI is closed.

### Affected version

`0.0.414`

### Steps to reproduce the behaviour

1. Open CLI
2. `/model`
3. Claude Sonnet 4.6
4. Effort level: `high`
5. Close CLI
6. Open CLI

### Expected behaviour

Effort level preserved.