Claude Code: Fix /api/trigger routing through a2a-proxy

The /api/trigger endpoint was falling into the catch-all proxy to
OpenClaw, which doesn't know about this route. Add explicit routing
to proxy /api/trigger to the FastAPI backend (A2A_PORT).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/a2a-proxy.cjs

@@ -275,6 +275,11 @@ const server = http.createServer((req, res) => {
     return proxyRequest(req, res, A2A_PORT);
   }
 
+  // API trigger endpoint → FastAPI backend (resolves A2A deadlock)
+  if (pathname === '/api/trigger') {
+    return proxyRequest(req, res, A2A_PORT);
+  }
+
   // State endpoint for Office frontend polling
   if (pathname === '/api/state' || pathname === '/status') {
     res.writeHead(200, {