Function parse_sammy_inp 

pub fn parse_sammy_inp(content: &str) -> Result<SammyInpConfig, SammyParseError>

Parse a SAMMY .inp file (minimal, for Phase 1 transmission cases).

Extracts: isotope info (Card 2), broadening params (Card 5), sample params (Card 6), data type keyword, and spin group definitions (Card 10).