Add Opencode as a supported option for MCP setup

### Problem or Motivation

**hs mcp setup** doesn't support Opencode 

<img width="703" height="167" alt="Image" src="https://github.com/user-attachments/assets/e687bf47-807e-4406-a048-78040c69da23" />

### Proposed Solution

Add Opencode as an option for setting up MCP

### Alternatives Considered

_No response_

### Additional Context

_No response_