Fix #4612: Return non-zero exit code when CLI session ends with error (#4621)

Signed-off-by: jalateras <jima@comware.com.au>

crates/goose-cli/src/cli.rs

@@ -1247,6 +1247,7 @@ pub async fn cli() -> Result<()> {
                 .await;
                 if let Err(e) = session.interactive(None).await {
                     eprintln!("Session ended with error: {}", e);
+                    std::process::exit(1);
                 }
                 Ok(())
             };