Function class_hover_from_index 

pub fn class_hover_from_index(
    word: &str,
    fqn: Option<&str>,
    indexes: &[(Url, Arc<FileIndex>)],
) -> Option<Hover>

Build a hover for a class/interface/trait/enum found by short name in the workspace index.

fqn is the fully-qualified name the caller resolved word to (e.g. via a use ... as Alias import), when known. Across a large workspace many unrelated classes can share a short name (and even the same local alias), so when fqn is available a candidate whose own cls.fqn matches it exactly is preferred over the first short-name match found. Falls back to the first short-name match when fqn is None (no use import to disambiguate a genuinely ambiguous bare reference).