feat(layout): finalize p01 and p02 changes

Complete UI foundation and app layout implementation, stabilize container health checks, and archive both OpenSpec changes after verification.

frontend/tests/component/sidebar.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, it } from 'vitest';
+import Sidebar, { isSectionVisible } from '../../src/lib/components/layout/Sidebar.svelte';
+
+describe('Sidebar component', () => {
+  it('exports a component module', () => {
+    expect(Sidebar).toBeDefined();
+  });
+
+  it('supports role-based visibility checks', () => {
+    expect(isSectionVisible({ title: 'ADMIN', roles: ['superuser'], items: [] }, 'superuser')).toBe(true);
+    expect(isSectionVisible({ title: 'ADMIN', roles: ['superuser'], items: [] }, 'manager')).toBe(false);
+    expect(isSectionVisible({ title: 'PLANNING', items: [] }, null)).toBe(true);
+  });
+});