Function parse_yaml 

pub fn parse_yaml(input: &str, budget: Budget) -> Result<bool, ScanError>

Return true if the YAML exceeds any budget.

Parameters:

• input: YAML text (UTF-8).
• budget: limits to enforce.

Returns:

• Ok(true) if a budget was exceeded (reject).
• Ok(false) if within budget.
• Err(ScanError) on parser error.

This only scans the parser event stream; it does not deserialize a YAML value.