NEW YORK - A battle broke out Friday for control of Wachovia, as Wells Fargo agreed to pay $14.8 billion for the struggling bank, while Citigroup and federal regulators insisted that Citi’s earlier and lower-priced takeover offer go forward. The surprise announcement that Wachovia Corp. agreed to be acquired by San Francisco-based Wells Fargo & Co. in the all-stock deal — without government assistance — upended what had appeared to be a carefully examined arrangement and caught regulato