Server wide search, not just WP generated “pages” ??

I’m evaluating WP and the first issue I see is that there will be no way to search across all files on the server, including all static/generated WP “pages” and all other .html pages which comprise the site.

We’d need a separate search engine for .html files, the WP search engine for WP “pages” — this is a usability nightmare. And as a practical matter, is there even a way to put a third-party search engine’s search box within a WP template??

Right now it looks like WP is all or nothing. Either every iota of content is WP generated and WP searchable, or forget WP.

We may just have to forget WP for this reason alone. Is there a plugin for a server-wide search?