design: apply Pixel design system tokens (Fira Sans/Code, CSS vars, badge helpers); add Playwright E2E setup + auth spec

playwright.config.ts

@@ -0,0 +1,21 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './e2e',
+  fullyParallel: false, // run serially — shared demo tenant
+  forbidOnly: !!process.env.CI,
+  retries: 1,
+  workers: 1,
+  reporter: [['html', { outputFolder: 'playwright-report' }], ['line']],
+  use: {
+    baseURL: process.env.E2E_BASE_URL || 'http://192.168.1.167:3002',
+    trace: 'on-first-retry',
+    screenshot: 'only-on-failure',
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'], headless: true },
+    },
+  ],
+});