Shortcut to cycle through my Custom Agents

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

Currently, if I want to change my custom agent, I have to do a command (/agent) and then select the one I need. It makes changing the agents a little tedious.

### Proposed solution

I propose we do a combination of keys that will allow me to quickly cycle to my custom agents, similar to how we can cycle trough the agent modes (plans, autopilot, regular)

### Example prompts or workflows

_No response_

### Additional context

In an internal discussion about this issue, someone else mentioned that it was strange you can't pass a name to `/agent` directly, you must pick from a list.