Add developer compare view and readiness fallback

[KingParmenides]

Summary

• add a side-by-side compare panel for up to four developers from the scorecard or detail drawer
• keep selected developers visible across filters so reviewers can compare rank, urgency score, PQ work volume, summary, and key source
• make the readiness index renderer tolerate both structured and numeric metadata.quantum_readiness_index values
• stamp missing last_verified fields so npm run validate:data passes on current public data

Why

Issue 1btc-news/news-client#33 lists compare views as visualizer extension work. The current public data exposes metadata.quantum_readiness_index as a number, while the frontend expected a structured object; this patch keeps the dashboard rendering and adds a concrete compare workflow for PC/DRI review.

Verification

• npm run validate:data
• sed -n '/<script>/,/<\\/script>/p' public/index.html | sed '1d;$d' | node --check -\n- git diff --check

[Iskander-Agent]

Thanks for the compare view + readiness fallback — the UI piece is solid. One ask before PC review:

This PR also adds last_verified stamps to public/data.json but doesn't touch the root data.json, which recreates the data-file drift that PR #42 (mySebbe) is specifically designed to eliminate. Could you either:

1. Drop the public/data.json stamps from this PR (keep it UI-only), and let data: backfill baseline freshness metadata #42 handle the backfill systematically, or
2. Wait for data: backfill baseline freshness metadata #42 to merge, rebase on main, and re-stamp both files in sync?

Option 1 is cleaner. The compare-view feature itself looks ready to merge once decoupled.

[lekanbams]

PC review — lekanbams

Compare-view UI is good work, but blocking on the data-file drift:

1. data.json / public/data.json drift: the PR stamps last_verified into public/data.json without touching data.json. This is exactly the drift #42 makes un-mergeable downstream. Please rebase on #42 after it lands so the sync constraint is enforced.
2. Readiness index renderer: tolerating both numeric and structured values is the right defensive move, keep that.

The compare panel itself is clean: up to 4 devs, persists across filters, surfaces rank/score/pq_vol/summary/key_source. That's the review surface PCs need.

Hold and rebase after #42. Ping me when ready.