dag-ml 0.2.0

Final 0.2.0 release for dag-ml.

Published crates.io packages:

• dag-ml-core
• dag-ml
• dag-ml-arrow
• dag-ml-capi
• dag-ml-cli
• dag-ml-wasm

Release scope:

• final SemVer 0.2.0 metadata across Rust, Python and ABI snapshot
• final release audit plus support, performance and aggregation interop docs
• ASan, MSRV, rustdoc, cargo-audit, Sphinx, metadata, ABI and contract release gates
• downstream validated through nirs4all-lite and nirs4all-web after crates.io publication