Function parse_literal_sql_source 

pub fn parse_literal_sql_source(
    language: SourceLanguage,
    source_path: &str,
    input: &str,
) -> DataDocument

Extracts focused literal SQL calls from a supported source language.

Dynamic, interpolated, concatenated, and unparseable query expressions are marked incomplete and remain unlinked. The function intentionally returns a document rather than an error so it can degrade safely inside focused source extractors.