Prepare Cell Render v0.2.0

[Tom-R-Main]

Summary

• promote the accumulated image, diagram, color, and visual-review work to v0.2.0
• refresh the release checklist and changelog boundary
• add a lean Zig 0.16 CI job covering formatting, 235 tests, build, and CLI smoke paths

Local verification

• Zig formatting check
• 235/235 tests
• debug build
• ReleaseFast benchmark build and run
• density and quadrant CLI smoke tests

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 11002010dc

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Pin checkout to a published major version

The inspected CI workflow references actions/checkout@v7, but that major version is not published, so every pull-request and main push run stops while resolving the first action and none of the formatting, tests, build, or smoke checks execute. Pin this step to a supported published release such as actions/checkout@v6.

Useful? React with 👍 / 👎.