Prepare command-generation 1.0 release candidate surface

[rickardvh]

Summary

• remove command-generation transitional built-in primitive definitions before 1.0
• prune package-level provisional exports from the public API docs and tests
• add 1.0.0rc1 release notes and a repeatable AW artifact-consumption proof script
• bump the package version to 1.0.0rc1

Proof

• uv run pytest -q
• uv run ruff check src tests scripts
• uv build

Cross-repo proof

• AW branch codex/aw-cg-1-0-consumption consumes this commit and passes its generated-package, operation-conformance, and artifact-consumption proofs.

Closes #58
Closes #59
Closes #60
Closes #61