Add review velocity landing-page section

[tangmingxiu11-commits]

Summary

• add a focused Review Velocity section to the landing page
• explain clearer acceptance criteria, reviewable proof, creator cadence, and payout readiness
• include a compact example task-health panel with reward, status, queue, approval, and health signals
• place the section after the existing Looking For section without adding dependencies

Closes #130

Verification

• npx tsc --noEmit
• git diff --check
• npm run build
• Browser QA at http://127.0.0.1:3021
  • desktop: section renders, CTAs/cards/health panel visible, no horizontal overflow
  • mobile 390x844: CTAs stack cleanly, cards stack cleanly, no horizontal overflow

Note

npm run lint currently opens Next.js' interactive ESLint setup prompt because this checkout does not include an ESLint config yet, so it could not run as a non-interactive validation command.