fix(ui): centralize contextual help and navigation presentation

Verified with the coordinated workspace changes by devkit full run
2026-09-08T225814-186389-0000-3e3ed7cd (all seven phases passed).
This shared UI pass does not mark the individual module reviews complete.

tests/test_interface_documentation_contract.py

@@ -101,7 +101,9 @@ class NotificationsInterfaceDocumentationContractTests(unittest.TestCase):
             "useUnsavedDraftGuard",
         ):
             self.assertIn(component, settings)
-        self.assertIn("DocumentationHelpLink", widget)
+        contribution = (REPO_ROOT / "webui/src/module.ts").read_text(encoding="utf-8")
+        self.assertIn("documentation: NOTIFICATIONS_DOCUMENTATION", contribution)
+        self.assertNotIn("DocumentationHelpLink", widget)
 
 
 if __name__ == "__main__":