Premium Analytics: Add Post highlights widget

[dognose24]

Fixes WOOA7S-1526. Part of WOOA7S-1622.

Why

The post/page detail page (shipped in #50096) has no widget showing how a post performed over its lifetime. This adds the "Post highlights" widget — all-time views, likes, and comments for the post being viewed — porting the Jetpack Stats post detail Highlights card into Premium Analytics.

Proposed changes

• New jpa/post-detail-highlights widget: three lifetime metric tiles (Views / Likes / Comments) fetched from the proxied stats/post/{id} endpoint via the existing useStatsPost hook.
• The widget is the first consumer of the post scope plumbing: it reads reportParams.post_id (seeded from the detail page URL through WidgetRoot) inside the inner component. Without a post scope — e.g. added to the main dashboard — it renders a scopeless empty state without firing a request.
• Scope note vs the Calypso original: the Calypso card also shows the post's title, date, and thumbnail, but on the Premium Analytics detail page those are owned by the page's summary header (post-summary-card), so the widget renders only the metric tiles to avoid duplicating the header. The likes-list card next to it in Calypso is WOOA7S-1528's separate widget.
• Storybook: Default, NoPostScope (the scopeless empty state), and WidgetDashboardWithWidget stories, with a local stats/post mock and a hasPostScope control.
• Not included: a default-layout seed for the post-detail page. No seeding mechanism exists yet for that page (tab layouts are client-side preferences that start empty) — building one is parent-issue scope (WOOA7S-1622), so for now the widget is added via the widget picker.

Related product discussion/links

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

No. The widget reads the existing stats/post endpoint through the established proxy.

Verification

Storybook registers and renders all stories for the widget (Default, NoPostScope, WidgetDashboardWithWidget); pnpm run typecheck, eslint, and the widget-audit checklist (shape/contract/chrome/tokens/i18n/JSDoc) all pass. Not yet exercised against a live post-detail page — the testing instructions below cover that pass.

Storybook story index

packages-premium-analytics-widgets-postdetailhighlights--docs
packages-premium-analytics-widgets-postdetailhighlights--default
packages-premium-analytics-widgets-postdetailhighlights--no-post-scope
packages-premium-analytics-widgets-postdetailhighlights--widget-dashboard-with-widget

Testing instructions

• From projects/packages/premium-analytics: pnpm run typecheck, pnpm run build (or jetpack build --deps packages/premium-analytics).
• Storybook (pnpm run storybook:dev from projects/js-packages/storybook): open Packages/Premium Analytics/Widgets/PostDetailHighlights — Default shows the three metric tiles with mock totals; NoPostScope shows the scopeless empty state; the dashboard story renders the framed card.
• On a Jetpack-connected site with the dashboard: open a post detail page (?page=jetpack-premium-analytics#/post/<post-id>), enter edit mode, and add the "Post highlights" widget from the picker.
• Confirm the tiles show the post's all-time views, likes, and comments (cross-check against the same post on the legacy Stats post detail page).
• Add the widget to the main (site-level) dashboard and confirm it renders the "Open a post or page report…" empty state instead of erroring.

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Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report

[dognose24]

🤖 Review-cycle summary — 36c1bb6d → c2698951

3 rounds; CI green; claude[bot] LGTM on re-review; no human comments pending.

What changed during the cycle

Commits added:

• c2698951f5 — Address review: drop obsolete picker-preview aspect-ratio rule

Review threads addressed:

Source	Comment	Resolution
claude[bot]	Unexplained [inert] aspect-ratio rule with a selector no sibling uses	Removed entirely — it was the obsolete picker-preview hack #50294 dropped package-wide; written here from a stale copy of the old AGENTS.md guidance (c2698951f5). Re-review confirmed no regression (this widget has no images, so no inert image-sizing rule is needed either).
claude[bot]	MetricTile/METRIC_FORMAT duplicated with latest-post	Acknowledged — promote to widgets-toolkit when a third consumer appears; the upcoming post-detail widgets (table, likes) are list-shaped.
claude[bot]	Hand-rolled loading/error/empty states	Conscious choice matching the latest-post metric-card precedent; zero tiles for a post with no engagement is intended.

Unaddressed (flagged for owner):
None.

CI: all required checks passing.

[Nikschavan]

Thank you for the changes, added two comments.

[dognose24]

Parking this as a draft: the new design spec for the post detail Traffic view folds the highlights metrics (Views / Comments / Likes) into a single Performance card (metric header + comparative trend chart + granularity control) rather than a standalone tiles card, so this widget as designed here is superseded. The reusable pieces — the shared stats-post fixture and the reportParams.post_id scope plumbing — will carry over to the Performance widget. Not closing yet pending the Linear ticket's disposition.

[dognose24]

Closing in favor of #50457: the new design spec folds these highlights metrics into the post detail Performance card (metric tabs + comparative view-trend chart), which that PR delivers. The reusable pieces from this PR — the shared stats-post fixture, the reportParams.post_id scope plumbing, and the WidgetState handling — were carried over there.