Backend:
- Add POST /v1/mcp/servers/test endpoint reusing DiscoverTools()
- Add GET /v1/mcp/servers/{id}/tools for discovered tool listing
- Add MCPToolLister interface and wire through gateway
Frontend:
- Add Test Connection button with success/error feedback in MCP form
- Replace agent ID text input with agent select dropdown in grants dialog
- Replace tool allow/deny text inputs with multi-select from server tools
- Add MCP tools dialog for viewing connected server tools
- Widen MCP dialogs to sm:max-w-xl