[codex] Add release changelog

[dankritz]

Summary

• Add a root CHANGELOG.md grouped by VibeStack release labels: 0.1a, 0.2b, 0.2c, and 0.2d.
• Summarize notable user-facing features, fixes, documentation, release-channel safety, and Doctor troubleshooting changes from git history.

Validation

• npm exec prettier -- --check CHANGELOG.md

Notes

• Also fast-forwarded local main from origin/main and pruned stale remote-tracking refs before creating this branch.
• Removed local stale Codex branches whose upstream refs were gone and whose patches are already equivalent to main.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• CHANGELOG.md

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_{Reviewed by grok-code-fast-1 · 103,572 tokens}