Switch to ES module exports for wws runtime

- Replace module.exports with export default
- wws uses ES modules, not CommonJS
- Fixes 'module is not defined' error

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

api/index.js

@@ -2,7 +2,6 @@
 // Path: /api
 
 async function handler(request) {
-  // CORS headers for browser requests
   const corsHeaders = {
     'Access-Control-Allow-Origin': '*',
     'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
@@ -37,5 +36,5 @@ async function handler(request) {
   })
 }
 
-// Export for wws
-module.exports = { handler }
+// ES Module export for wws
+export default handler