Task-003: Publish GitHub CAD review summaries

[rsasaki0109]

Linked task

Task-003

Summary

• Generate a deterministic github-summary.md beside every CAD review bundle.
• Report semantic changes, regenerated dimensions, mass, volume, mesh counts, and expected-effect evidence with explicit units.
• Fail the review command after preserving artifacts when a declared expected effect does not pass.
• Add a Design Review workflow that publishes the Markdown job summary and uploads the HTML/GIF/JSON review bundle.
• Update the README and Git-native documentation.

Implementation notes

The Design Graph remains the source of truth. Review geometry is regenerated from an in-memory dry run, the input document is not mutated, and GitHub I/O is isolated to Actions. Summary and artifact publication use always() so failed checks retain review evidence.

Tests added

• Markdown table escaping
• Passing and failing expected-effect status
• Validation failure for unmet expected effects
• Generated github-summary.md artifact content

Validation

• cargo fmt --all -- --check
• cargo clippy --all-targets -- -D warnings
• cargo test --workspace
• Flagship review generated locally from examples/bracket.ocad.d and examples/agent/review_width_patch.json

Docs updated

• README workflow/status section
• docs/architecture/git-native-workflow.md
• docs/api/git-native.md

Known limitations

The workflow intentionally dogfoods the checked-in flagship bracket patch; automatic discovery of arbitrary changed CAD documents is outside Task-003.