Boost: Show performance and settings on one page

[LiamSarsfield]

Fixes BOOST-716

Proposed changes

Show scores, history or upsell, and “Optimize your speed” on one scrolling page. Preserve sub-pages and old Settings links as section destinations. Reuse the existing Settings composition.

Related product discussion/links

See ticket above.

Does this pull request change what data or activity we track or use?

Record one Overview page view per page activation. Stop recording Settings page views; hidden and immediately redirected routes emit none.

Testing instructions

Production build, 511 Jest tests, TypeScript, ESLint and Stylelint passed. On local Docker with SCRIPT_DEBUG=false, checked free/full history, top/section positions, old URLs, all four return paths, and RTL at 1280/782. Both modernization e2e jobs passed on the rebased head.

Filter off: rendered legacy dashboard HTML is identical (85,394 bytes). Full-page differences include asset versions and trunk’s My Jetpack data. Legacy screenshots differ only in a few antialiased pixels at 1280/782.

State	1280	782
Free	Top / Section	Top / Section
History	Top / Section	Top / Section
Free RTL	Top / Section	Top / Section
History RTL	Top / Section	Top / Section

Former Settings URL

Legacy: base 1280, final 1280, base 782, final 782.

Follow-up

Amend the frozen route contract and parity checklist rows that name the tabs once this lands.

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 2 files.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/boost/app/assets/src/js/lib/modern/routes.ts	30/30 (100.00%)	0.00%	0 💚
projects/plugins/boost/routes/dashboard/stage.tsx	77/77 (100.00%)	0.00%	0 💚

Full summary · PHP report · JS report