Quickly switch between pre-set model configs

### Describe the feature or problem you'd like to solve

Enable rapid model/effort switching for better efficiency

### Proposed solution

As developer I want in many cases to use the strongest model with highest effort level available. However, typing /model, choosing the model with arrows, then choosing the effort level with right left is cumbersome and might cause be to avoid it and therefore not use the right model for the task.

My proposal is to enable mapping keyboard shortcuts to pre-set models and effort so I can quickly switch between them based on the task.
I assume there are other use cases for custom keyboard mapping.

Alternatively, add option to create custom commands, like for example "/cheap" will switch to a pre-set model I choose with pre-set effort level.
Using an approach like "/agent cheap" can work but it changes tools/behavior and not generic enough.

Another option is to create another command (e.g. "/pmodel") which shows a list of 5 pre-set model configurations I can quickly choose by number.

### Example prompts or workflows

_No response_

### Additional context

_No response_

A issue não nomeia arquivos, testes ou pontos de entrada. Comece localizando o fluxo existente de /model e qualquer tratamento de atalhos de teclado ou comandos personalizados. Compare as abordagens propostas com o comportamento atual da CLI; done deve fornecer uma maneira rápida de alternar entre configurações predefinidas de modelo e esforço.

Escrita pelo modelo de indexação a partir do texto da issue.