modified: .gitignore

modified:   .vscode/launch.json
	new file:   e2e/playwright-collect-coverage.spec.ts
	modified:   package-lock.json
	modified:   package.json
	modified:   playwright.config.ts
	new file:   scripts/merge-lcov.cjs
	new file:   scripts/normalize-lcov.cjs
	new file:   scripts/playwright-collect-coverage.cjs
	new file:   scripts/remap-and-report.cjs
	modified:   vite.config.ts
	new file:   vitest.config.ts

e2e/playwright-collect-coverage.spec.ts

@@ -0,0 +1,57 @@
+// e2e/playwright-collect-coverage.spec.ts
+import fs from 'fs';
+import path from 'path';
+import { test } from '@playwright/test';
+
+const EVAL_TIMEOUT_MS = 5000;
+const WRITE_TIMEOUT_MS = 15000;
+
+function withTimeout<T>(p: Promise<T>, ms: number, onTimeout?: () => void) {
+  let timer: NodeJS.Timeout | undefined;
+  const timeout = new Promise<T>((res) => {
+    timer = setTimeout(() => {
+      onTimeout?.();
+      // @ts-ignore resolve null on timeout
+      res(null);
+    }, ms);
+  });
+  return Promise.race([p, timeout]).then((r) => {
+    if (timer) clearTimeout(timer);
+    return r;
+  });
+}
+
+test.afterEach(async ({ page }, testInfo) => {
+  try {
+    console.log(`Collecting coverage for: ${testInfo.title}`);
+
+    // Evaluate coverage in page, but don't hang forever
+    const evalPromise = page.evaluate(() => (globalThis as any).__coverage__ || null);
+    const coverage = await withTimeout(evalPromise, EVAL_TIMEOUT_MS, () => {
+      console.warn('page.evaluate for coverage timed out');
+    });
+
+    if (!coverage || Object.keys(coverage).length === 0) {
+      console.log('No coverage collected (empty or timed out).');
+      return;
+    }
+
+    const dir = path.join(process.cwd(), '.nyc_output');
+    await fs.promises.mkdir(dir, { recursive: true });
+
+    const safeTitle = (testInfo.title || 'test').replace(/[^a-zA-Z0-9-_]/g, '_').slice(0, 120);
+    const worker = typeof testInfo.workerIndex === 'number' ? testInfo.workerIndex : process.pid;
+    const filename = path.join(dir, `coverage-e2e-w${worker}-${Date.now()}-${safeTitle}.json`);
+
+    // write asynchronously, bounded by timeout
+    const writePromise = fs.promises.writeFile(filename, JSON.stringify(coverage));
+    await withTimeout(writePromise, WRITE_TIMEOUT_MS, () => {
+      console.warn('Writing coverage file timed out');
+    });
+
+    console.log('Wrote coverage:', filename);
+  } catch (error: unknown) {
+    const msg = error instanceof Error ? error.message : String(error);
+    console.warn('Failed to collect coverage from page:', msg);
+  }
+});