Function resolve_hover 

pub fn resolve_hover(
    parts: &[String],
    file_uri: &Url,
    root: &Path,
    project_cache: &ProjectCache,
    types_lock: &Types,
) -> Option<Hover>

Resolve hover information for an identifier.

Takes the dot-qualified identifier parts (from goto_definition::find_reference_at_position()), resolves it against the ProjectCache (SQLite), and formats the output schema as Markdown.

Column schemas are retrieved via two-tier lookup: ProjectCache first (typecheck columns), then Types (types.lock) as fallback.

Returns

Some(Hover) with Markdown content if the identifier resolves to a known object, None otherwise.