fix(ui): unify heading help, table sizing and navigation contracts

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.

webui/src/components/NavigationPreferenceEditor.tsx

@@ -26,6 +26,7 @@ export default function NavigationPreferenceEditor({ items, productAreas = [], v
   const instructionsId = useId();
   const inherited = inheritedNavigationLayout(items, scope, productAreas);
   const editable = materializeNavigationLayout(value, inherited);
+  const layoutStatus = value === null ? "inherited" : (editable.separators?.length ?? 0) > 0 ? "grouped" : "flat";
   const byId = new Map(items.map((item) => [navigationId(item), item]));
   const inheritedScope = scope === "system" ? "module" : scope === "tenant" ? "system" : "tenant";
   const ancestorLocked = (id: string) => Boolean(byId.get(id)?.navigationLayers?.[inheritedScope]?.locked);
@@ -104,6 +105,9 @@ export default function NavigationPreferenceEditor({ items, productAreas = [], v
         <p className="muted small-note" id={instructionsId}>{navigationText("help")}</p>
         <Button onClick={() => onChange(null)} disabled={disabled || value === null}>{navigationText("inherit")}</Button>
       </ActionToolbar>
+      <p className="muted small-note" data-navigation-layout-status={layoutStatus}>
+        {navigationText(`${layoutStatus}_status`)}
+      </p>
       <ActionToolbar className="navigation-preference-add">
         <select aria-label={translateText(navigationText("available"))} value={addId} disabled={disabled || available.length === 0} onChange={(event) => setSelectedModule(event.target.value)}>
           {available.length === 0 && <option value="">{translateText(navigationText("all_added"))}</option>}