feat: public API, SEO and existing surfaces

features/media_library.feature

@@ -289,7 +289,8 @@ Feature: The media library holds every uploaded image as a library-level asset
       Given article 1 "Kitchen Renovation" is online and article 2 "Backyard Notes" is a draft, both containing image 1's url, and article 3 does not
       When the client sends GET /v1/media/1/usage with a valid cookie
       Then the response status is 200
-      And the body is [{"id": 1, "title": "Kitchen Renovation", "published": true}, {"id": 2, "title": "Backyard Notes", "published": false}]
+      And the body is [{"id": 1, "title": "Kitchen Renovation", "published": true, "story_id": 1, "lang": "en"}, {"id": 2, "title": "Backyard Notes", "published": false, "story_id": 2, "lang": "en"}]
+      And the items are one per version, and each carries the stored story_id and lang of its article (lang "" for an unassigned article), as in features/localization_public_api_and_surfaces.feature
 
     Scenario: An unused image has an empty array, not null
       When the client sends GET /v1/media/4/usage