UX overhaul: 1-click row navigation, Exchange tab, Applications page (#69)

Row click in ExecutionExplorer now navigates directly to RoutePage with
View Transition instead of expanding an inline panel. Route column is a
clickable link for context-free navigation. Search state syncs to URL
params for back-nav preservation, and previously-visited rows flash on
return. RoutePage gains an Exchange tab showing execution metadata/body/
errors. New /apps page lists application groups with status and route
links, accessible from TopNav.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/router.tsx

@@ -6,6 +6,7 @@ import { OidcCallback } from './auth/OidcCallback';
 import { ExecutionExplorer } from './pages/executions/ExecutionExplorer';
 import { OidcAdminPage } from './pages/admin/OidcAdminPage';
 import { RoutePage } from './pages/routes/RoutePage';
+import { ApplicationsPage } from './pages/apps/ApplicationsPage';
 
 export const router = createBrowserRouter([
   {
@@ -24,6 +25,7 @@ export const router = createBrowserRouter([
         children: [
           { index: true, element: <Navigate to="/executions" replace /> },
           { path: 'executions', element: <ExecutionExplorer /> },
+          { path: 'apps', element: <ApplicationsPage /> },
           { path: 'apps/:group/routes/:routeId', element: <RoutePage /> },
           { path: 'admin/oidc', element: <OidcAdminPage /> },
         ],