Boost: build the Settings tab on the modernization chassis

[keoshi]

Summary

PR 3 of the Boost modernization umbrella (#48717) — builds the Settings tab on the modernization chassis with full parity for every legacy module's advanced controls.

Cornerstone Pages is a collapsible card at the top, then every Boost module renders as a Card.Root with its toggle, description, and per-module sub-feature panel below. The chassis stays behind rsm_jetpack_ui_modernization_boost — flip the filter on to see it, flip off and the legacy dashboard returns unchanged.

What ships in each card

• Cornerstone Pages — URL textarea with plan-aware validation (same-site URL guard, "homepage already included" guard, 1-page free / 10-page premium limit), Include default pages action with plan-aware truncation tooltip, Prerender Cornerstone Pages toggle, free-plan upgrade Notice. Saving regenerates Cloud CSS when enabled and invalidates LCP state — same side effects as the legacy panel.
• Critical CSS (manual) — Status card with file count + timestamp, ProgressBar while pending, Regenerate Critical CSS button, provider-error summary linking to the legacy Critical CSS Advanced page, regenerate-suggestion banner driven by critical_css_suggest_regenerate, manual→auto upgrade Notice.
• Cloud CSS (auto) — Same Status panel with auto-mode copy. Filtered out on free.
• LCP — Status panel with last-optimized timestamp + Optimize action firing lcp_state.request-analyze, error notice for failed pages.
• Page Cache — Setup-error notice with Retry + Dismiss, Show options collapsible with bypass-patterns textarea + Save, logging toggle, See logs link, Clear cache action.
• Minify JS / Minify CSS — Reusable Exclude handles panel with comma-separated input + summary chip + Load default handles action backed by the <entry>_default read-only entries.
• Image CDN — Adjust image quality (3 RangeControls + Lossless toggles for JPEG / PNG / WebP) + Auto-resize lazy images sub-toggle on premium; free-plan upgrade Notice otherwise.
• Image Guide — "Image resizing is unavailable" warning Notice when the server can't run Imagick or GD.

Architecture

• Generic useDataSyncEntry< Schema > + useDataSyncAction hooks (in _inc/lib/) compose every per-module read/write/action surface against the existing data-sync REST endpoints. No dependency on @automattic/jetpack-react-data-sync-client — keeps the modernized bundle from shipping a second copy of React Query.
• Per-module hooks: useCriticalCssState, useLcpState, usePageCacheSettings / useRunPageCacheSetup / useClearPageCache, useImageCdnQuality, useCornerstonePagesList / useCornerstonePagesProperties / useSetCornerstonePagesList, usePremiumFeatures.
• Premium gating: usePremiumFeatures().has( slug ) — slugs cornerstone-10-pages, cloud-critical-css, image-cdn-quality, image-cdn-liar.
• Settings page renders as a 660px-capped column, flat list (no section headings), behind rsm_jetpack_ui_modernization_boost.

Stacked on PR 2

This PR's base is update/boost-modernization-overview (#48726). Once PR 2 squash-merges, re-point this PR's base to trunk from the GitHub UI.

Test plan

• Flip add_filter( 'rsm_jetpack_ui_modernization_boost', '__return_true' ); and load wp-admin/admin.php?page=jetpack-boost. Switch to Settings.
• Toggle every module on and off — each card's toggle round-trips through modules_state; the toggle disables while writing.
• Cornerstone Pages — expand the card; add a custom URL; save; reload and confirm it persists. Try saving a same-site URL and a wrong-site URL — the wrong-site URL surfaces a validation error and disables Save. Click Include default pages when present.
• Critical CSS (manual) — click Regenerate Critical CSS; the ProgressBar appears, the file count updates when complete, the timestamp ticks up.
• LCP — enable the module; the Status panel reports the analysis state; click Optimize to retrigger.
• Page Cache — expand Show options; add a bypass pattern; save; toggle logging; click Clear cache + See logs.
• Minify JS / CSS — expand the per-card panel; add a handle; save; reload and confirm the summary chip updates. Click Load default handles to merge the curated list in.
• Image CDN (free) — turn the module on; the upgrade Notice appears with an Upgrade now button pointing at ?page=my-jetpack#/add-boost-image-cdn.
• Image CDN (premium) — Quality sliders + Lossless toggles + Auto-resize lazy images render and round-trip.
• Image Guide — on a server without Imagick/GD the "unavailable" warning appears.
• Flip the filter off → reload → legacy Boost dashboard renders unchanged.

🤖 Generated with Claude Code

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Code Coverage Summary

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