fix: correctly propagate exit codes without printing them

src/namespace.rs

@@ -224,10 +224,12 @@ where
     match status {
         nix::sys::wait::WaitStatus::Exited(_, 0) => Ok(()),
         nix::sys::wait::WaitStatus::Exited(_, code) => {
+            // If the child reported an error (e.g., setup failure), return it.
+            // Otherwise, just forward the exit code without an error message.
             if let Some(msg) = child_error {
                 Err(anyhow!("{}", msg))
             } else {
-                Err(anyhow!("Child process exited with code {}", code))
+                std::process::exit(code);
             }
         }
         nix::sys::wait::WaitStatus::Signaled(_, sig, _) => {