Function get_validation_errors_formatted 

pub fn get_validation_errors_formatted(
    db: &impl Db,
    doc_file: TextFile,
) -> Result<Vec<String>, QueryError>

Validate document against schema and return formatted error strings.

Resolves the schema internally from the document’s $schema extension, workspace config, or file name heuristics.

Returns empty vec if no schema is found or parsing failed. Returns formatted error messages suitable for display.