Function decode_algol_located_with_budget 

pub fn decode_algol_located_with_budget(
    codec: CodecId,
    source_id: impl Into<String>,
    source: &str,
    budget: &mut DecodeBudget,
) -> Result<LocatedExpr>

Decodes Algol source into a LocatedExpr under an explicit decode budget.

The budget bounds token count, nesting depth, and string/trivia sizes so a hostile input cannot exhaust resources. Otherwise behaves like decode_algol_located.