fix: 修复阻塞事件循环的警告

将 serial.tools.list_ports.comports() 和串口验证移到线程池执行
避免阻塞 HA 事件循环，消除 asyncio_blocking_operations 警告

custom_components/sigmesh_gateway/config_flow.py

@@ -30,6 +30,20 @@ from .const import (
 )
 
 
+def _get_serial_ports() -> list:
+    """获取可用串口列表（在同步线程中执行）."""
+    import serial.tools.list_ports
+    return serial.tools.list_ports.comports()
+
+
+def _test_serial_connection(device: str, baudrate: int) -> bool:
+    """测试串口连接（在同步线程中执行）."""
+    import serial
+    test_serial = serial.Serial(device, baudrate=baudrate, timeout=0.5)
+    test_serial.close()
+    return True
+
+
 class SigMeshGatewayConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
     """SigMesh Gateway 配置流程."""
 
@@ -48,29 +62,24 @@ class SigMeshGatewayConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
         self._errors = {}
 
         if user_input is not None:
-            # 验证串口连接
+            # 验证串口连接（在线程池中执行，避免阻塞事件循环）
             try:
-                import serial
-
-                test_serial = serial.Serial(
+                await self.hass.async_add_executor_job(
+                    _test_serial_connection,
                     user_input[CONF_SERIAL_DEVICE],
-                    baudrate=user_input.get(CONF_BAUDRATE, DEFAULT_BAUDRATE),
-                    timeout=0.5,
+                    user_input.get(CONF_BAUDRATE, DEFAULT_BAUDRATE),
                 )
-                test_serial.close()
                 self._user_input = user_input
                 # 进入配网配置步骤
                 return await self.async_step_prov_config()
-            except serial.SerialException as e:
+            except (ImportError, serial.SerialException) as e:
                 self._errors[CONF_SERIAL_DEVICE] = f"无法打开串口：{e}"
             except Exception as e:
                 self._errors["base"] = f"验证失败：{e}"
 
-        # 获取可用串口列表
+        # 获取可用串口列表（在线程池中执行，避免阻塞事件循环）
         try:
-            import serial.tools.list_ports
-
-            ports = serial.tools.list_ports.comports()
+            ports = await self.hass.async_add_executor_job(_get_serial_ports)
             port_list = [
                 selector.SelectOptionDict(value=p.device, label=f"{p.device} - {p.description}")
                 for p in ports