A team can do a Salesforce integration if they have licensed Sitecore CDP, or they could do a bespoke Salesforce integration.
Is there no more support for front-end search out of the box? Is it required either provision another Solr instance, or use Coveo or another search vendor?
Sitecore XM Cloud is focused on a being an API-first, headless, composable, content management solution. Sitecore will be offering a separate composable site search offering for front end websites.