test(e2e): Playwright photos-ready flow + visual evidence (#65)

Drive batch → pick calibration → Mask (Black) → Axis → Measure Calculate →
Photos ready against set1-48x2 fixtures on local vite preview. Capture
screenshots under tests/e2e/artifacts/; commit README + small evidence JPEGs.

frontend/playwright.config.ts

@@ -0,0 +1,30 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * M2 #65 — Playwright visual evidence against local vite preview (not ubudual).
+ * Artifacts land in tests/e2e/artifacts/ (png churn gitignored; README committed).
+ */
+export default defineConfig({
+  testDir: './tests/e2e',
+  fullyParallel: false,
+  forbidOnly: !!process.env.CI,
+  retries: 0,
+  workers: 1,
+  timeout: 180_000,
+  expect: { timeout: 30_000 },
+  reporter: [['list'], ['html', { open: 'never', outputFolder: 'tests/e2e/playwright-report' }]],
+  use: {
+    baseURL: 'http://127.0.0.1:4173',
+    trace: 'retain-on-failure',
+    screenshot: 'only-on-failure',
+    video: 'off',
+    ...devices['Pixel 7'],
+  },
+  webServer: {
+    command: 'npm run build && npm run preview -- --host 127.0.0.1 --port 4173',
+    url: 'http://127.0.0.1:4173',
+    reuseExistingServer: !process.env.CI,
+    timeout: 180_000,
+  },
+  outputDir: 'tests/e2e/test-results',
+});