Introduce the `obicompactvec` crate, featuring a two-tier, memory-mapped integer vector that uses a primary `u8` array with a sentinel for overflow dispatch and a sparse L1-resident index for fast random access. Implement builder and reader modules with zero-copy serialization and comprehensive test coverage. Update `obilayeredmap` to replace the default hash function with a cache-line-optimized `Mphf`, adding explicit bounds checking and duplicate-slot detection. Add documentation for both modules and update project configuration files accordingly.
Replace `ph` with `ptr_hash` and introduce `epserde` and `rayon` dependencies. Refactor MPHF construction to leverage parallel iteration, eliminating intermediate `Vec<u64>` allocations and reducing memory footprint. Add a `n_kmers` field to track and serialize total kmer counts, alongside three zero-allocation iterators for efficient chunk traversal. Include comprehensive unit tests for the new iterators and update CLAUDE.md to enforce explicit dependency validation policies.
Introduces the `obilayeredmap` crate (v0.1.0), implementing an append-only, disk-backed k-mer index using a minimal perfect hash function (MPHF). The module features memory-mapped reads, buffered writes, custom error handling, partition metadata persistence, and comprehensive unit tests. Also adds a reverse complement benchmark for `obikseq` and updates `Cargo.lock` with the new dependencies.