fix(page-display): isolate header component page scopes

tests/widget-system/page-display-contract.test.cjs

@@ -225,5 +225,8 @@ test('save contract rejects invalid input and round-trips canonical nested value
     generic_page_excludes_center: false,
     templated_public_user_home: true,
     templated_user_center: true,
+    home_excludes_page: false,
+    home_excludes_public_home: false,
+    home_excludes_user_center: false,
   })
 })