fix(federated-css): resolve CI test failures and port conflicts

- Remove duplicate 'workers' property in playwright.config.ts
- Add killPort() function to clean up ports before starting servers
- Fix macOS compatibility by avoiding GNU-specific xargs -r flag
- Add extra port cleanup for Next.js servers to prevent EADDRINUSE errors

This fixes the CI failure where port 8084 was already in use when the
Next.js server tried to start, causing tests to timeout.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ScriptedAlchemy

federated-css/scripts/start-all.cjs

@@ -1,4 +1,4 @@
-const { spawn } = require('node:child_process');
+const { spawn, execSync } = require('node:child_process');
 const waitOn = require('wait-on');
 const path = require('node:path');
 const fs = require('node:fs');
@@ -15,6 +15,18 @@ function run(cmd, args) {
   return spawn(cmd, args, { stdio: 'inherit', cwd: root, shell: true });
 }
 
+function killPort(port) {
+  try {
+    // Kill any process on the port (macOS/Linux compatible)
+    const pids = execSync(`lsof -ti tcp:${port} 2>/dev/null || true`, { encoding: 'utf8' }).trim();
+    if (pids) {
+      execSync(`kill -9 ${pids} 2>/dev/null || true`, { stdio: 'ignore' });
+    }
+  } catch (e) {
+    // Ignore errors, port might not be in use
+  }
+}
+
 async function main() {
   const reactConsumers = [
     { dir: 'combination-of-4', port: 3001, serve: true },
@@ -37,6 +49,10 @@ async function main() {
 
   const procs = [];
 
+  // Kill all potentially conflicting ports first
+  console.log('[federated-css] cleaning up ports...');
+  [...reactConsumers.map(c => c.port), ...exposes, ...nextConsumers.map(c => c.port)].forEach(killPort);
+
   console.log('[federated-css] starting consumers-react (sequential servers)...');
   for (const { dir, port, serve } of reactConsumers) {
     const cwd = path.join('consumers-react', dir);
@@ -102,6 +118,8 @@ async function main() {
 
   console.log('[federated-css] starting Next consumers (sequential dev servers)...');
   for (const { dir, port } of nextConsumers) {
+    // Extra cleanup for each Next.js port in case previous one didn't clean up properly
+    killPort(port);
     const cwd = path.join('consumers-nextjs', dir);
     const p = run('pnpm', ['-C', cwd, 'run', 'start']);
     procs.push(p);