feat: add internationalization message platform

tests/features/reference-feature/reference-contract.test.ts

@@ -72,10 +72,10 @@ describe("reference feature boundary contracts", () => {
       createdAt: "2026-07-26T00:00:00.000Z",
     });
     if (!("id" in model)) throw new Error("expected one model");
-    expect(toReferenceView(model, () => "formatted")).toEqual({
+    expect(toReferenceView(model)).toEqual({
       resourceId: "reference-1",
       title: "Example",
-      createdAtLabel: "formatted",
+      createdAt: "2026-07-26T00:00:00.000Z",
     });
   });