v0.9.0

New features

• New query engine implementation (no user-facing API changes).
• New logging context and verbosity system.

API changes

• cooler.balance_cooler now uses the same default argument values as the CLI.

Schema

• cooler balance now inserts divisive_weights: False metadata to balancing weights.

Maintenance

• Dropped Python 2 support.
• Removed deprecated io module.
• Deprecated tools module; renamed parallel.
• Various dependency maintenance upgrades.
• Modernized CI and dev tools.
• Migrated to pyproject.toml and modernized packaging infra.