Fix API Collection icon rendering for external references

Ensures API Collections are correctly identified as collectionGroup kind in linkable entities by using DocumentationContentRenderer.roleForArticle logic. This fixes cross-framework references where API Collections were incorrectly showing Article icons instead of Collection Group icons.

rdar://135837611

Author: RalucaP

Sources/SwiftDocC/LinkTargets/LinkDestinationSummary.swift

@@ -1017,7 +1017,18 @@ private extension DocumentationNode {
         // specialized articles, like sample code pages, that benefit from being treated as articles in
         // some parts of the compilation process (like curation) but not others (like link destination
         // summary creation and render node translation).
-        return metadata?.pageKind?.kind.documentationNodeKind ?? kind
+        let baseKind = metadata?.pageKind?.kind.documentationNodeKind ?? kind
+
+        // For articles, check if they should be treated as API Collections (collectionGroup).
+        // This ensures that linkable entities have the same kind detection logic as the rendering system,
+        // fixing cross-framework references where API Collections were incorrectly showing as articles.
+        if baseKind == .article,
+           let article = semantic as? Article,
+           DocumentationContentRenderer.roleForArticle(article, nodeKind: kind) == .collectionGroup {
+            return .collectionGroup
+        }
+
+        return baseKind
     }
 }
 

Tests/SwiftDocCTests/LinkTargets/LinkDestinationSummaryTests.swift

@@ -833,8 +833,6 @@ class LinkDestinationSummaryTests: XCTestCase {
     /// Tests that API Collections (articles with Topics sections) are correctly identified as `.collectionGroup`
     /// kind in linkable entities, ensuring cross-framework references display the correct icon.
     func testAPICollectionKindForLinkDestinationSummary() async throws {
-        throw XCTSkip("Test will be enabled after implementing the fix")
-
         let symbolGraph = makeSymbolGraph(
             moduleName: "TestModule",
             symbols: [makeSymbol(id: "test-class", kind: .class, pathComponents: ["TestClass"])]