feat: 完成四轮子独立pid调试

crates/bench/src/lib.rs

@@ -786,8 +786,10 @@ pub mod hil {
 
             let mut policy = MotorPolicy::new();
             policy.configure(config.esc.esc_id, config.esc.current_limit, VelocityGains::ZERO);
+            let runtime_guard = runtime.enter();
             let bus = EscBus::spawn(link, vec![config.esc.clone()], config.bus.clone(), policy)
                 .map_err(|e| BenchError::Bus(e.to_string()))?;
+            drop(runtime_guard);
             let motor = bus
                 .motor(esc_id)
                 .ok_or_else(|| BenchError::Bus(format!("esc {esc_id} missing from the bus")))?
@@ -938,6 +940,22 @@ pub mod hil {
                 open_link("ignored", 2_000_000, crate::CanSpeed::M1, Some("can-not-real"));
             assert!(missing_interface.is_err(), "不存在的 CAN 接口必须报错");
         }
+
+        #[test]
+        fn evaluator_spawns_bus_without_an_outer_tokio_runtime() {
+            let (link, peer) = can::CanLink::pair(8);
+            // 测试只关心 runtime 启动；立刻关闭对端，避免假链路堵住 1kHz 命令发送。
+            drop(peer);
+            let mut config = config();
+            config.startup_timeout = Duration::from_millis(1);
+
+            let result = BenchEvaluator::open(link, config);
+
+            assert!(
+                matches!(result, Err(BenchError::NoFeedback { esc_id: 1, .. })),
+                "应当在自有 runtime 中启动总线并因无反馈返回错误"
+            );
+        }
     }
 }