Re-home FOSS Artifact Registry organization surface into ee/ (monolith/S01 Steps 1-2)

Context

The monolith already ships a minimal FOSS Artifact Registry (AR) organization surface: the slug-less /o/:organization_path/-/artifact_registry route, its controller, a placeholder view, the read_artifact_registry ability (granted to organization_user), and a "Go to Artifact Registry" entry point on the organization overview page. The AR feature is EE-only, so this surface must move to ee/ before the S01 feature steps build on it.

This issue covers Steps 1 and 2 of the monolith/S01 plan.

Scope

Step 1 - Re-home the FOSS overview AR entry point to ee/

  • Remove the "Go to Artifact Registry" link, the two AR-specific empty-state copy variants, the canReadArtifactRegistry mount data, and the can_read_artifact_registry helper key from the FOSS organizations/show overview page and its Jest spec.
  • Restore the entry point unchanged on EE via an override so the FOSS page no longer imports the generated artifactRegistryOrganizationIndexPath route helper.

Step 2 - Relocate the AR org page to ee/

  • Move the AR organization controller (#index, the slug-less Activation route), its placeholder view, route, and specs from FOSS into ee/.
  • Switch the controller to feature_category :artifact_registry (from :organization).
  • Move the read_artifact_registry organization_user grant into the EE organization policy; the permission-definition YAML and admin-role reference stay FOSS as inert declarations.

Acceptance

  • FOSS overview page renders without importing artifactRegistryOrganizationIndexPath and shows no AR link; an EE build shows the AR link and empty-state copy exactly as before.
  • The slug-less /o/:organization_path/-/artifact_registry still routes and renders identically on EE; on FOSS the route is absent (404) and organization_user is disallowed :read_artifact_registry.
  • The moved request and routing specs pass under ee/spec; the generated routes JS regenerates cleanly.

Notes

  • No artifact_registry_ui feature flag yet (it arrives with the shared seam). The whole organization UI is already behind ui_for_organizations.
  • The shared EE seam (feature flag, gating concern, acme stub slug, activation-route gating) builds on this and is tracked in #599226 (closed).

References