Well. Nothing is permanently lost -- even if it's unrecoverable, the entire site exists on my own machine. But it looks like this may take a little while to sort out. (I'm suddenly very glad I re-registered the domain name myself yesterday. As long as "project-apollo.net" will always resolve where I tell it to, everything's at least long-term coo'.)
So, any recommendations for webhosting services that don't suck and can service a 223 megabyte site such as project-apollo...? Yes, at this point I do believe I'm going to pick up shop and move out. I wouldn't have much grounds for complaint if Yahoo! had actually informed me of any impending problems or at least given me a way to contact them after dropping the bomb (the customer service number I found after searching the Web is closed until "normal business hours," yeah, like that makes any sense in 2006) but if they aren't going to make any effort whatsoever then they can go to hell as far as I'm concerned.