Connect the version list artifact read to the schema

What does this MR do and why?

Artifact Registry is an unreleased closed-beta feature. Its GraphQL schema is not complete, so the frontend fills gaps with Apollo local resolvers marked @client. This MR moves the artifact page closer to the real schema, and fixes a bug that broke the page on real data.

Schema binding

• get_artifact.query.graphql now reads from the schema. @client is gone from image(id:) and package(id:).
• Version and manifest connections are not ready in the schema, so they stay local. @client moved down, onto the versions/manifests connection itself.
• That move removed a workaround: sort and paging arguments no longer need duplicating onto package()/image(). Verified in the browser: the request now carries only organizationId, name, and artifactId.

Mock layer

• Connections now build their rows from the artifact id, via versionLadderFor(id) and manifestLadderFor(id). versionsCount uses the same source, so the count matches the rows.
• The local image resolver is deleted; nothing selects it that way any more.
• The local package resolver stays, for the version detail page (commit 53e0e385), guarded so Apollo does not overwrite the schema's answer.

Bug fix and tests

• artifactDisplayName no longer joins the npm scope onto name, fixing a duplicated heading like @acme/@acme/ui-components. This was already happening in the artifact list, which uses the same helper, so it is not a regression from this MR.
• New schema-generated fixtures (Maven, npm, image) replace hand-written mocks in version_list_spec.js.
• A new :js feature spec covers package and image headings and the not-found case, and runs be_axe_clean on the populated pages.
• Two Storybook stories are fixed, since their handlers stopped matching the new resolvers.

The bug: the old mock resolver looked up an id in a list it generated itself, so a real id matched nothing, and the page showed "The Artifact Registry service is unavailable." Confirmed fixed on a live GDK.

No changelog trailer is added, since Artifact Registry is unreleased. The change touches no database, no migration, and nothing security sensitive.

References

• #618416 (closed): "Connect the version list view to the schema (monolith/S14 Step 25)"

This MR does not fully close the issue. The versions and manifests connections still need three schema arguments (sort on both, includeReferrers on manifests) and the version attribution fields (createdBy, project, gitCommitSha) before their @client directive can come off.

Screenshots or screen recordings

Both lists were checked in a browser against a live Artifact Registry, on these two routes:

• Version list: /o/default/-/artifact_registry/acme/repositories/maven-repository/019ffef0-842d-7670-b4ea-f350acb3ca56
• Manifest list: /o/default/-/artifact_registry/acme/repositories/oci-repository/01a05af1-ca65-776f-a351-2ccaa9ad51ef

Before and after images still need attaching to the table below.

Before	After

How to set up and validate locally

1. Set up a GDK with Artifact Registry backed by real data.
2. Visit a hosted Maven repository detail page.
3. Click an artifact row.
4. Confirm the version list loads and the heading shows the Maven coordinates (groupId:artifactId).
5. Repeat steps 2 to 4 on a hosted OCI repository to reach the manifest list.

Before this change, the rows region showed the "Artifact Registry service is unavailable" alert instead of the version or manifest list.

Verification

• Jest: 52 suites, 1726 tests passed (yarn jest ee/spec/frontend/packages_and_registries/artifact_registry).
• RSpec: 8 examples, 0 failures (3 fixture examples, 5 feature examples, including the axe check).
• eslint, prettier, and rubocop: clean.

MR acceptance checklist

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