WOOA7S-1502: Port Stats Shares widget

[kangzj]

Fixes WOOA7S-1502

Proposed changes

Ports the Jetpack Stats Shares (Publicize) module into a registered Premium Analytics widget (jpa/shares).

• New widgets/shares/ workspace package: package.json, widget.json, widget.ts, render.tsx, shares.module.css, and a Storybook story.
• Renders a LeaderboardChart where each row is a connected social account (icon + name via the toolkit LeaderboardLabel) with its follower count.
• Data comes from the existing useStatsPublicize data hook. The Publicize endpoint is non-time-series (built on useStatsQuery) and has no date range or comparison period, so the widget always shows current follower counts; the max attribute trims the row count client-side (max = 0 shows all).
• Honors the Stats-widget contract: host-owned chrome (no body heading), WidgetLoadingOverlay only when loading with no rows yet, emptyStateText for the empty state, --wpds-* tokens in the CSS Module, and the picker-preview aspect-ratio block.
• Changelog entry added.

No changes to packages/data, packages/widgets-toolkit, or @automattic/charts. The Storybook root (projects/packages/premium-analytics/widgets) was already registered in projects.js, so that file is unchanged. Because the shared registerReportMocks helper does not cover the Publicize endpoint, the story registers a small story-scoped apiFetch middleware to serve it — keeping the entire diff inside widgets/shares/ rather than modifying the shared toolkit mocks.

Related product discussion/links

• https://linear.app/a8c/issue/WOOA7S-1502

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

No. It surfaces existing Jetpack Stats Publicize data through a new dashboard widget.

Testing instructions

Live-dashboard verification pending — handled centrally; Storybook + audit + eslint pass locally.

• pnpm --dir projects/js-packages/storybook run storybook:dev → open Packages / Premium Analytics / Widgets / Shares and confirm the Default, WithComparison, and WidgetDashboardWithWidget stories render a populated leaderboard (WithComparison shows the same counts with no deltas, as documented).
• Verified locally: /widget-audit shares clean, eslint clean, and jetpack build packages/premium-analytics succeeds (widget bundles and jpa/shares appears in the generated widget registry).

[jp-launch-control]

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

[github-actions]

Thank you for your PR!

When contributing to Jetpack, we have a few suggestions that can help us test and review your patch:

• ✅ Include a description of your PR changes.
  
• ✅ Add a "[Status]" label (In Progress, Needs Review, ...).
  
• ✅ Add testing instructions.
  
• ✅ Specify whether this PR includes any changes to data or privacy.
  
• ✅ Add changelog entries to affected projects
  

This comment will be updated as you work on your PR and make changes. If you think that some of those checks are not needed for your PR, please explain why you think so. Thanks for cooperation 🤖

---

Follow this PR Review Process:

1. Ensure all required checks appearing at the bottom of this PR are passing.
2. Make sure to test your changes on all platforms that it applies to. You're responsible for the quality of the code you ship.
3. You can use GitHub's Reviewers functionality to request a review.
4. When it's reviewed and merged, you will be pinged in Slack to deploy the changes to WordPress.com simple once the build is done.

If you have questions about anything, reach out in #jetpack-developers for guidance!

[kangzj]

Live dashboard verification — Shares

Rendered on the connected Premium Analytics dashboard (Insights tab, raven env, blog 254382195) with real data and zero console errors.