Replaces parallel random-access unitig iteration with a sequential mmap-based iterator for MPHF construction, eliminating the build-time `.idx` dependency by deferring index generation until after persistence. Updates `CLAUDE.md` to treat existing code as a hypothesis, mandating proactive removal of obsolete legacy constructs rather than preserving them out of inertia.
Introduce a secondary layer iteration to open `SrcLayerData` alongside the unitig reader for concurrent metadata access. This refactors the merge routine to handle kmer deduplication and per-layer data initialization simultaneously. Also corrects a typo in `rebuild_layer.rs` where `openopen_sequential` is renamed to `open_sequential`.
Refactored `MphfLayer::build` to accept an `EvidenceKind` parameter, routing to exact (index-based, parallel MPHF, writes `evidence.bin`) or approximate (sequential mmap iterator, writes `fingerprint.bin`) pipelines. Introduced `CanonicalKmerIter` for memory-mapped, chunked k-mer iteration with O(1) resets via `Arc<Mmap>`. Updated layer and map APIs to forward evidence kind, added `push_layer` for count matrices, and adjusted tests and public exports accordingly.
Refactor `Kmer`, `SuperKmer`, and chunk reader into optimized, generic representations with compile-time length parameters and bitwise operations. Update the pipeline and scheduler to support batch processing, 1→N flat transformations, and multi-source merging. Introduce an approximate evidence mode using b-bit fingerprints and `.idx` files, alongside existing exact mode. Update CLI documentation, minimizer selection, and query output schema accordingly.
Eric Coissac