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/breadcrumbs.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, it } from 'vitest';
+import Breadcrumbs, { generateBreadcrumbs } from '../../src/lib/components/layout/Breadcrumbs.svelte';
+
+describe('Breadcrumbs component', () => {
+  it('exports a component module', () => {
+    expect(Breadcrumbs).toBeDefined();
+  });
+
+  it('generates correct crumbs', () => {
+    const crumbs = generateBreadcrumbs('/reports/allocation-matrix');
+    expect(crumbs.map((crumb) => crumb.label)).toEqual(['Home', 'Reports', 'Allocation Matrix']);
+    expect(crumbs[2].href).toBe('/reports/allocation-matrix');
+  });
+});