Update extensions/cli/src/commands/chat.ts

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

Author: chezsmithy

extensions/cli/src/commands/chat.ts

@@ -446,7 +446,7 @@ async function runHeadlessMode(
 ): Promise<void> {
   // Critical validation: Ensure we have a prompt in headless mode
   // This prevents the CLI from hanging in TTY-less environments
-  if (!prompt) {
+  if (!prompt && !options.prompt?.length && !options.agent) {
     throw new Error(
       'Headless mode requires a prompt. Use: cn -p "your prompt"\n' +
         'Or pipe input: echo "prompt" | cn -p\n' +