ignore SIGCHLD so children are reaped

src/user/mod.rs

@@ -554,6 +554,9 @@ pub enum SubCmd {
 
 #[tokio::main]
 pub async fn main() {
+    // Auto-reap child processes (channel daemons outlive the supervisor)
+    unsafe { libc::signal(libc::SIGCHLD, libc::SIG_IGN); }
+
     // Initialize the Qwen tokenizer for direct token generation
     let tokenizer_path = dirs::home_dir().unwrap_or_default()
         .join(".consciousness/tokenizer-qwen35.json");