Function complete_package_names_generic 

pub async fn complete_package_names_generic(
    registry: &dyn Registry,
    prefix: &str,
    limit: usize,
    insert_range: Range,
) -> Vec<CompletionItem>

Generic package name completion using any Registry implementation.

Searches the registry for packages matching prefix and returns up to limit completion items, each with its textEdit set to replace insert_range. Returns empty vec if prefix is shorter than 2 characters or longer than 200 characters. A result whose name fails build_package_completion’s crate::is_safe_package_name gate is silently dropped rather than surfaced as an error, matching the fallback-search completion builder’s convention (create_package_completion_item in deps-lsp).