test(@angular/build): add e2e for a larger project with Vitest

Adds an end-to-end test to verify Vitest runner performance and correctness
with a larger number of generated components, services, and pipes. This test
executes the suite in both JSDOM and browser environments to ensure stability
and proper functionality under scale.

Author: clydin

tests/legacy-cli/e2e/tests/vitest/larger-project.ts

@@ -0,0 +1,60 @@
+import { ng } from '../../utils/process';
+import { applyVitestBuilder } from '../../utils/vitest';
+import assert from 'node:assert';
+import { installPackage } from '../../utils/packages';
+import { exec } from '../../utils/process';
+
+export default async function () {
+  await applyVitestBuilder();
+
+  const artifactCount = 100;
+  // A new project starts with 1 test file (app.spec.ts)
+  // Each generated artifact will add one more test file.
+  const initialTestCount = 1;
+
+  // Generate a mix of components, services, and pipes
+  for (let i = 0; i < artifactCount; i++) {
+    const type = i % 3;
+    const name = `test-artifact-${i}`;
+    let generateType;
+
+    switch (type) {
+      case 0:
+        generateType = 'component';
+        break;
+      case 1:
+        generateType = 'service';
+        break;
+      default:
+        generateType = 'pipe';
+        break;
+    }
+
+    await ng('generate', generateType, name, '--skip-tests=false');
+  }
+
+  const totalTests = initialTestCount + artifactCount;
+  const expectedMessage = new RegExp(`${totalTests} passed`);
+
+  // Run tests in default (JSDOM) mode
+  const { stdout: jsdomStdout } = await ng('test', '--no-watch');
+  assert.match(jsdomStdout, expectedMessage, `Expected ${totalTests} tests to pass in JSDOM mode.`);
+
+  // Setup for browser mode
+  await installPackage('playwright@1');
+  await installPackage('@vitest/browser-playwright@4');
+  await exec('npx', 'playwright', 'install', 'chromium', '--only-shell');
+
+  // Run tests in browser mode
+  const { stdout: browserStdout } = await ng(
+    'test',
+    '--no-watch',
+    '--browsers',
+    'ChromiumHeadless',
+  );
+  assert.match(
+    browserStdout,
+    expectedMessage,
+    `Expected ${totalTests} tests to pass in browser mode.`,
+  );
+}