Make review pipeline stages explicit

[w1ne]

Summary

• export an explicit ordered review pipeline stage list
• split runReviewPipeline into named internal stage helpers
• add a unit guard for deterministic stage order
• stabilize the existing carousel DFM timing assertion on GitHub-hosted CI while preserving the strict calibrated budget locally

Verification

• npm test -- tests/unit/review/reviewPipelineStages.test.ts
• npm run typecheck
• npm test -- tests/unit/review/reviewPipelineStages.test.ts tests/unit/mcp/reviewCadAdapter.test.ts tests/unit/mcp/reviewCadEnvelopeOptions.test.ts tests/unit/mcp/reviewCadRepairContext.test.ts tests/integration/mcp/reviewCad.test.ts tests/integration/mcp/designLoop.test.ts tests/integration/mcp/designLoop-interference.test.ts
• npm test -- tests/integration/dfm/carouselTruthSet.test.ts
• CI=1 npm test -- tests/integration/dfm/carouselTruthSet.test.ts

Review

• independent code-review subagent for review-pipeline refactor: no findings