Update GitHub Actions workflow to use setup-go v5 and align with latest tooling practices.
Update version to 4.4.15 in version.txt and pkg/obioptions/version.go.
Add comprehensive documentation for the canonical super-kmer strategy, including:
- Analysis of index v1 limitations
- Experimental observations on super-kmer efficiency
- Detailed pipeline for building v3 index
- Explanation of minimizer-canonization
- Description of unitig construction and frequency filtering
- Storage format specifications for v3
- Aho-Corasick matching implementation
This change introduces a major improvement in index compactness and performance through the use of canonical super-kmers, unitigs, and efficient storage formats.
