HLD/LLD reconciliation pass + first PyPI release.

Surface complete: 4 subcommands functional; 224 tests passing across
the 6-cell + bio-tools CI matrix (Python 3.11/3.12/3.13 x ubuntu/macos
+ bioconda real-binary integration); ruff clean.

What's new vs v0.1.0:
- coverage subcommand emits the 9-col output spec'd in the HLD (median
  + fraction_at_>=Nx columns derived from mosdepth's global.dist.txt)
- .dict auto-generation per HLD spec (extract pre-flight, cached) so
  fresh users don't hit opaque Picard errors on a freshly-downloaded
  FASTA
- Real-binary CI job (bioconda) catches the smoke-test class of bug
  automatically rather than requiring manual GCP discovery
- Performance benchmark + pgen-samplebind composition shape-contract
  tests per LLD §18 #19 + #20
- HLD CLI ref now matches the shipped --enable-baq positive flag

See CHANGELOG.md for the full per-commit history.