chore(release): prepare Python 2.0.2 and Rust 2.0.1

[Seth Juarez (sethjuarez)]

Summary

• bump Python runtime version to 2.0.2 and update the Python changelog for Harden runtime parity conformance #548
• bump Rust workspace crates to 2.0.1 and update inter-crate dependency versions
• update release manifest metadata for Python and Rust

Validation

• uv run ruff check prompty tests
• uv run pytest tests\test_memory.py tests\model\test_vector_conformance.py -q
• uv run --with flit flit build --format wheel
• uv run --with flit flit build --format sdist
• cargo check --workspace --locked
• cargo package --workspace --locked --allow-dirty
• git --no-pager diff --check

Release notes

After this PR merges, the Rust publish workflow can publish rust/2.0.1 when the PR has the release: rust label. Python publish still requires creating/pushing the python/2.0.2 tag against the merged commit so the source version matches the tag.