e1dab86daf06b87cc4ba0100236f29d114ac42ec
Introduce a new `fingerprint` module that stores packed B-bit vectors via memory-mapped files. Expose the module publicly and add `build_approx_evidence` to `Layer` and `MphfLayer` for generating compact `fingerprint.bin` files. Implement `find_approx` for fast, probabilistic kmer lookups using configurable bit-widths. Update dependencies to `bitvec` v1 and add `cacheline-ef`, `epserde`, and `memmap2` to support the new storage and serialization logic.