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/erika/oshw.c

@@ -0,0 +1,79 @@
+/*
+ * Licensed under the GNU General Public License version 2 with exceptions. See
+ * LICENSE file in the project root for full license information
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+
+#include "oshw.h"
+#include "intel_i210.h"
+#include "ethercat.h"
+
+#if !defined(__gnu_linux__)
+#include <machine/endian.h>
+#else
+#include <endian.h>
+#define __htons(x) htobe16(x)
+#define __ntohs(x) be16toh(x)
+#endif
+
+ec_adaptert	adapters [DEVS_MAX_NB];
+
+/**
+ * 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.
+ */
+inline uint16 oshw_htons(uint16 host)
+{
+	// __htons() is provided by the bare-metal x86 compiler
+	return __htons(host);
+}
+
+/**
+ * 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.
+ */
+inline uint16 oshw_ntohs(uint16 network)
+{
+	// __ntohs() is provided by the bare-metal x86 compiler
+	return __ntohs(network);
+}
+
+/** Create list over available network adapters.
+ * @return First element in linked list of adapters
+ */
+ec_adaptert* oshw_find_adapters(void)
+{
+	ec_adaptert *ret = NULL;
+	if (eth_discover_devices() >= 0) {
+		for (int i = 0;; ++i) {
+			struct eth_device *dev = eth_get_device(i);
+			if (dev == NULL) {
+				adapters[i-1].next = NULL;
+				break;
+			}
+			strncpy(adapters[i].name, dev->name, MAX_DEVICE_NAME);
+			adapters[i].next = &adapters[i+1];
+		}
+		ret = &(adapters[0]);
+	}
+	return ret;
+}
+
+/** 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)
+{
+}
+
+extern int ec_slavecount;
+