ci(review): dispatch AI review after CI

[Terry-Mao]

Summary

• Add a repository CI workflow that runs tests and Python compile checks, then dispatches the existing AI review workflow after successful PR CI.
• Remove direct pull_request triggering from review-pr.yml so automated AI review runs through workflow_dispatch after CI or explicit @AGENT_LOGIN /review comments.
• Keep ci.yml out of install.sh sync and document how target repositories should dispatch review-pr.yml from their own CI success path.

Validation

• python3 -m unittest discover -s .github/tests
• python3 .agents/skills/review-pr/scripts/validate_review_json.py pr_diff.txt review.json
• python3 .github/scripts/validate_review_json.py pr_diff.txt review.json
• python3 .github/scripts/validate_local_review_result.py --baseline-status .local_review_baseline.status

Fixes #152

[github-actions]

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