feat(portal-frontend): add router with worklist and case-detail routes

Empty placeholder components for worklist-list and case-detail,
wired into app.routes.ts (legacy/:id and owned/:id share one page
component since the rendered shape is identical). Replaces the CLI
welcome template with a minimal shell rendering <router-outlet>.

portal-frontend/src/app/app.routes.ts

@@ -1,3 +1,11 @@
 import { Routes } from '@angular/router';
 
-export const routes: Routes = [];
+import { CaseDetailPage } from './case-detail/case-detail/case-detail';
+import { WorklistList } from './worklist/worklist-list/worklist-list';
+
+export const routes: Routes = [
+  { path: '', component: WorklistList },
+  { path: 'legacy/:id', component: CaseDetailPage },
+  { path: 'owned/:id', component: CaseDetailPage },
+  { path: '**', redirectTo: '' },
+];