Abstracts k-mer storage using a `RawKmer` alias and `KMER_BITS` constant to simplify bit manipulation and enable future extension to larger types. Updates bit-shifting and masking logic across `kmer.rs` and `packed_seq.rs` to prevent overflow and improve type safety. Adapts the MPHF layer to iterate over indexed canonical k-mers with explicit slot bounds validation and bit-level encoding. Fixes test suite compilation errors by correcting method names, adding tuple destructuring, and passing the required `IndexMode::Exact` parameter.
Eric Coissac
657f964dda