Expose Popover in Admin UI extension targets

[Fionoble]

What changed

• Add the generated Popover.d.ts contract for Admin UI extensions.
• Include Popover in StandardComponents, making it available to block, action, print, app-home, and other standard Admin render targets.
• Regenerate target documentation metadata and add a minor changeset.

Why

This completes the public client-contract side of shop/world PR #2011726, which registers the s-popover renderer in Admin Web's shared Remote DOM component set.

Testing

• yarn build
• yarn lint
• yarn type-check
• yarn test (no affected Jest suites)
• Verified generated target declarations for product block, product action, and app home import Popover.d.ts

[Fionoble]

/snapit

[shopify-github-actions-access]

🫰✨ Thanks @Fionoble! Your snapshots have been published to npm.

Test the snapshots by updating your package.json with the newly published versions:

"@shopify/ui-extensions": "0.0.0-snapshot-20260827192205",
"@shopify/ui-extensions-tester": "0.0.0-snapshot-20260827192205"