[FEATURE]: Add MCP OAuth authentication UI to settings #11478

Feature Request

Problem

Currently, users have no UI-based way to manage OAuth credentials for MCP (Model Context Protocol) servers. Authentication must be done through command-line tools or by manually editing configuration files, which is not user-friendly.

Proposed Solution

Add a dedicated MCP settings tab to the OpenCode settings dialog that allows users to:

• View all configured MCP servers and their authentication status
• Authenticate with OAuth-enabled MCP servers via browser flow
• Re-authenticate existing servers when credentials expire
• Logout/remove stored OAuth credentials
• See real-time authentication status updates

Benefits

• Improved UX: Users can manage MCP server authentication through a visual interface
• Discoverability: Users can see which servers need authentication
• Error visibility: Clear error messages when authentication fails
• Convenience: No need to use CLI commands for OAuth flows

Use Case

When a user adds an MCP server that requires OAuth (e.g., GitHub, Google Drive, Jira), they need an easy way to authenticate and manage those credentials without leaving the application.

Related

• Related to existing MCP OAuth infrastructure
• Complements existing command-line OAuth functionality
• Part of improving overall MCP user experience