bug: mcp/tools not switching when using /agent swap

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

WSL

### Expected behaviour

If I have 2 agents, let's call them "A" and "B". Agent A has access to certain MCP servers and Tools, A1, A2, ... Ax. Agent B has access to other MCP server and Tools B1, B2, ... Bx. Now I start a session with Q CLI with Agent A. It will load Agent A's MCPs and tools. Now I swap agents through /agent swap B. I would expect it would load Agent B's MCP Servers and Tools.

### Actual behaviour

Q switches the context to Agent B, but it keeps the MCPs and Tools from Agent A.

### Steps to reproduce

_No response_

### Environment

```yaml

```

Empieza reproduciendo el problema en WSL con dos agentes configurados y `/agent swap B`, confirmando que Agent B conserva los servidores MCP y las herramientas de Agent A. Sigue el manejo del cambio de agente y el comportamiento de recarga de MCP y herramientas; se considera terminado cuando cambiar de agente reemplaza los recursos disponibles por los configurados para el agente seleccionado.

Escrito por el modelo de indexación a partir del texto del issue.