A disappointing October sales report Thursday sent a clear signal to retailers that they’ll have to pull out all the stops to get shoppers into their stores this holiday as declining home values, tighter credit terms and rising gas prices appear to have left consumers feeling spent. The nation’s biggest chain stores posted the second consecutive month of weak sales results, underscoring their concerns that sales growth this holiday season could be the slowest in five years. “Consumers are exerting a lot of caution,” said Mandy Putnam, vice president at TNS Retail Forward Inc., a Columbus, Ohio-based market research and...