Function start_mcp_server_generic 

pub async fn start_mcp_server_generic<I: McpIo>(
    db: Arc<ThingsDatabase>,
    config: ThingsConfig,
    io: I,
) -> Result<()>

Generic MCP server implementation that works with any I/O implementation

This function is generic over the I/O layer, allowing it to work with both production stdin/stdout (via StdIo) and test mocks (via MockIo).