feat(motor): 自适应 PDO 窗口与通道活动指示，新增原生 SOEM 时序诊断

后端 PDO 循环改为按在线槽收缩状态窗口，稀疏总线下单槽每周期都能刷新，
并补上尾部槽的发现扫描游标；新增自旋节拍源（阈值/显式覆盖）、P 核识别
与线程级钉核，自旋期间释放 GIL 以免 HTTP 线程被饿死；启动时先关停旧实例，
避免两个进程争用 Npcap 适配器。

记录每拍完整时间线、GC stop-the-world 事件与网格跳拍数，经 /api/motor/dbg
导出用于归因固定频率的超时；配

soem-src/oshw/rtk/oshw.c

@@ -0,0 +1,53 @@
+/*
+ * Licensed under the GNU General Public License version 2 with exceptions. See
+ * LICENSE file in the project root for full license information
+ */
+
+#include "oshw.h"
+#include <stdlib.h>
+#include <lwip/inet.h>
+
+/**
+ * Host to Network byte order (i.e. to big endian).
+ *
+ * Note that Ethercat uses little endian byte order, except for the Ethernet
+ * header which is big endian as usual.
+ */
+uint16 oshw_htons(const uint16 host)
+{
+	uint16 network = htons (host);
+	return network;
+}
+
+/**
+ * Network (i.e. big endian) to Host byte order.
+ *
+ * Note that Ethercat uses little endian byte order, except for the Ethernet
+ * header which is big endian as usual.
+ */
+uint16 oshw_ntohs(const uint16 network)
+{
+	uint16 host = ntohs (network);
+	return host;
+}
+
+/* Create list over available network adapters.
+ * @return First element in linked list of adapters
+ */
+ec_adaptert * oshw_find_adapters(void)
+{
+   ec_adaptert * ret_adapter = NULL;
+
+   /* TODO if needed */
+
+   return ret_adapter;
+}
+
+/** Free memory allocated memory used by adapter collection.
+ * @param[in] adapter = First element in linked list of adapters
+ * EC_NOFRAME.
+ */
+void oshw_free_adapters(ec_adaptert * adapter)
+{
+	   /* TODO if needed */
+}