Fix wws runtime compatibility - use module.exports pattern

- Update api/index.js to use handler export format
- Update chat/index.js to use handler export format
- Update webhook/index.js to use handler export format
- Remove addEventListener('fetch') pattern incompatible with wws
- Remove URL API usage (not available in wws JS runtime)
- Remove spread operator for better compatibility

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

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

api/index.js

@@ -1,22 +1,17 @@
 // Health check and API info endpoint
 // Path: /api
 
-addEventListener('fetch', event => {
-  event.respondWith(handleRequest(event.request))
-})
-
-async function handleRequest(request) {
-  const url = new URL(request.url)
-
+async function handler(request) {
   // CORS headers for browser requests
   const corsHeaders = {
     'Access-Control-Allow-Origin': '*',
     'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
     'Access-Control-Allow-Headers': 'Content-Type, Authorization',
+    'Content-Type': 'application/json'
   }
 
   if (request.method === 'OPTIONS') {
-    return new Response(null, { headers: corsHeaders })
+    return new Response('', { headers: corsHeaders })
   }
 
   const response = {
@@ -38,9 +33,9 @@ async function handleRequest(request) {
   }
 
   return new Response(JSON.stringify(response, null, 2), {
-    headers: {
-      'Content-Type': 'application/json',
-      ...corsHeaders
-    }
+    headers: corsHeaders
   })
 }
+
+// Export for wws
+module.exports = { handler }