feat(web): vocabularies two-pane screen (list/create + terms/add) + nav

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/app.tsx

@@ -7,6 +7,9 @@ import { AppShell } from "./shell/app-shell";
 import { ObjectsPage } from "./objects/objects-page";
 import { ObjectDetail } from "./objects/object-detail";
 import { SelectPrompt } from "./objects/select-prompt";
+import { VocabulariesPage } from "./vocab/vocabularies-page";
+import { VocabularyTerms } from "./vocab/vocabulary-terms";
+import { SelectVocabularyPrompt } from "./vocab/select-vocabulary-prompt";
 
 const ObjectNewPage = lazy(() =>
   import("./objects/object-new-page").then((m) => ({ default: m.ObjectNewPage })),
@@ -47,6 +50,10 @@ export function App() {
                 }
               />
             </Route>
+            <Route path="/vocabularies" element={<VocabulariesPage />}>
+              <Route index element={<SelectVocabularyPrompt />} />
+              <Route path=":id" element={<VocabularyTerms />} />
+            </Route>
             <Route path="/" element={<Navigate to="/objects" replace />} />
           </Route>
         </Route>