[J] Rewrite consumer examples + onboarding docs for v3

[cbeaulieu-gt]

Parent epic: #273 · Spec: docs/superpowers/specs/2026-05-20-codex-pivot.md §10, §11 (#J)

Scope

Rewrite all consumer-facing docs to remove retired surfaces and document the v3 setup path.

Files to rewrite

• examples/README.md
• examples/claude-apply-fix.yml → examples/codex-apply-fix.yml
• examples/claude-ci-failure.yml → examples/codex-ci-failure.yml
• examples/claude-lint-failure.yml → examples/codex-lint-failure.yml
• examples/claude-pr-review.yml → remove (App-handled, no caller workflow needed)
• examples/claude-tag-respond.yml → remove (verb router retired)
• docs/consumer-onboarding.md
• CLAUDE.md (architecture rewrite, secrets table refresh)
• README.md

Content rules

• Remove all CLAUDE_CODE_OAUTH_TOKEN references
• Remove all GHCR overlay package install steps
• Remove all claude-*.yml@v2 uses: lines
• Replace with codex-*.yml@v3, OPENAI_API_KEY secret, App-handled PR review path

Lifecycle cleanup

Per CLAUDE.md lifecycle rule, retire legacy runtime spec + plan files (durable content extracted first):

• docs/superpowers/specs/2026-04-21-ci-claude-runtime-design.md
• docs/superpowers/plans/2026-04-22-ci-claude-runtime.md

Acceptance

A fresh consumer following the rewritten examples/README.md and docs/consumer-onboarding.md against glitchwerks/github-actions@v3 can complete setup without any reference to retired surfaces.

Test method: use a throwaway repo (e.g. cbeaulieu-gt/codex-pivot-consumer-test or fresh personal repo) as the consumer test bed. Acceptance met when a clean checkout of that test repo, following only the rewritten docs, can install the Codex App, open a test PR, and observe a Codex review post — with no reference to retired Claude/GHCR/OAuth surfaces in the consumer's workflow.

Gating

MUST merge before #K (v3 tag is cut).

🤖 Generated by Claude Code on behalf of @cbeaulieu-gt