Home-equity lending has been booming in 2004, drawing the attention of a lending industry hoping to offset a sharp drop in first mortgage refinance activity with a highly profitable alternative – and more scrutiny from federal regulators. Origination of home-equity loans – both closed-end seconds and revolving lines of credit – surged to an estimated $98.8 billion in the third quarter of this year, according to a new Inside Mortgage Finance analysis of the market.…