fix: allow async handlers in forward to support deferred events

Author: ethanndickson

src/node/services/agentSession.ts

@@ -396,7 +396,10 @@ export class AgentSession {
   }
 
   private attachAiListeners(): void {
-    const forward = (event: string, handler: (payload: WorkspaceChatMessage) => void) => {
+    const forward = (
+      event: string,
+      handler: (payload: WorkspaceChatMessage) => void | Promise<void>
+    ) => {
       const wrapped = (...args: unknown[]) => {
         const [payload] = args;
         if (
@@ -407,7 +410,7 @@ export class AgentSession {
         ) {
           return;
         }
-        handler(payload as WorkspaceChatMessage);
+        void handler(payload as WorkspaceChatMessage);
       };
       this.aiListeners.push({ event, handler: wrapped });
       this.aiService.on(event, wrapped as never);