Method SetActive

internal/config/config.go:355–366

SetActive switches the active profile and persists. Fails on an unknown name, no silent coercion. On Save failure it reverts in-memory Active so the live model and config.yaml stay in lockstep; otherwise the switch would stick this session but vanish on the next Bootstrap.

(name string)

// no silent coercion. On Save failure it reverts in-memory Active so the live
// model and config.yaml stay in lockstep; otherwise the switch would stick this
// session but vanish on the next Bootstrap.
func (c *Config) SetActive(name string) error {
	if _, ok := c.Models[name]; !ok {
		return fmt.Errorf("unknown model: %s", name)
	}
	prev := c.Active
	c.Active = name
	if err := c.Save(); err != nil {
		c.Active = prev
		return err
	}
	return nil
}