Restore review status rail

[selfcontained]

Summary

• restore the subtle review-level left status rail that was present before PR Polish review feedback sidebar and inline threads #766 merged
• use the existing waiting token for open and partially resolved reviews, and the working/success token for resolved reviews
• show a muted Review feedback header when an optional review summary is absent
• add focused coverage for open, partially resolved, resolved, and no-summary rows

Validation

• pnpm run check
• pnpm run finalize:web
• pnpm --filter @dispatch/web test (196 passed)
• pnpm run test:e2e (168 passed, 12 expected live-runtime skips)
• Playwright interaction on /agents/seed-agent-running-feature: expanded and collapsed a real no-summary review, then captured multiple reviews with one expanded