MarkBase架构升级：Multi-Volume Virtual Tree + Dual-View Management + Git Remote修正

核心功能：
- ✅ Categories/Series双视图管理（category_view.rs + import_markdown.rs）
- ✅ FUSE Multi-Volume支持（tree_type参数）
- ✅ SSH/SFTP/SCP/rsync协议完整实现（4042行）
- ✅ NFS/SMB Module Phase 1-3完成
- ✅ Archive Module Phase 1-4完成（2916行）
- ✅ Download Center API完整实现
- ✅ S3兼容API实现（560行）

Git配置修正：
- ✅ 删除错误origin（gitea.momentry.ddns.net）
- ✅ 删除m5max128（指向机器名）
- ✅ 设置origin = m5max128gitea.momentry.ddns.net/admin/markbase
- ✅ 设置m4minigitea = m4minigitea.momentry.ddns.net/warren/markbase

数据清理：
- ✅ 删除38个临时SQLite（保留accusys.sqlite、demo.sqlite）
- ✅ 删除.bak、test_*.bin、调试脚本等临时文件
- ✅ 删除临时目录（build/、download files/、raid_test/等）
- ✅ 更新.gitignore排除临时文件

架构优化：
- 52个文件修改，2434行新增，4739行删除
- Workspace成员整合（16个crate）
- 数据库状态：accusys.sqlite保留（主demo测试）

远程同步：
- ✅ 准备推送到m5max128gitea（远程Gitea）
- ✅ 准备推送到m4minigitea（本地Gitea）

research/iscsi/target_core_user.h

@@ -0,0 +1,188 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __TARGET_CORE_USER_H
+#define __TARGET_CORE_USER_H
+
+/* This header will be used by application too */
+
+#include <linux/types.h>
+#include <linux/uio.h>
+
+#define TCMU_VERSION "2.0"
+
+/**
+ * DOC: Ring Design
+ * Ring Design
+ * -----------
+ *
+ * The mmaped area is divided into three parts:
+ * 1) The mailbox (struct tcmu_mailbox, below);
+ * 2) The command ring;
+ * 3) Everything beyond the command ring (data).
+ *
+ * The mailbox tells userspace the offset of the command ring from the
+ * start of the shared memory region, and how big the command ring is.
+ *
+ * The kernel passes SCSI commands to userspace by putting a struct
+ * tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking
+ * userspace via UIO's interrupt mechanism.
+ *
+ * tcmu_cmd_entry contains a header. If the header type is PAD,
+ * userspace should skip hdr->length bytes (mod cmdr_size) to find the
+ * next cmd_entry.
+ *
+ * Otherwise, the entry will contain offsets into the mmaped area that
+ * contain the cdb and data buffers -- the latter accessible via the
+ * iov array. iov addresses are also offsets into the shared area.
+ *
+ * When userspace is completed handling the command, set
+ * entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate,
+ * and also set mailbox->cmd_tail equal to the old cmd_tail plus
+ * hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it
+ * should process the next packet the same way, and so on.
+ */
+
+#define TCMU_MAILBOX_VERSION 2
+#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
+#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
+#define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */
+#define TCMU_MAILBOX_FLAG_CAP_TMR (1 << 2) /* TMR notifications */
+#define TCMU_MAILBOX_FLAG_CAP_KEEP_BUF (1<<3) /* Keep buf after cmd completion */
+
+struct tcmu_mailbox {
+	__u16 version;
+	__u16 flags;
+	__u32 cmdr_off;
+	__u32 cmdr_size;
+
+	__u32 cmd_head;
+
+	/* Updated by user. On its own cacheline */
+	__u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
+
+} __packed;
+
+enum tcmu_opcode {
+	TCMU_OP_PAD = 0,
+	TCMU_OP_CMD,
+	TCMU_OP_TMR,
+};
+
+/*
+ * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
+ */
+struct tcmu_cmd_entry_hdr {
+	__u32 len_op;
+	__u16 cmd_id;
+	__u8 kflags;
+#define TCMU_UFLAG_UNKNOWN_OP 0x1
+#define TCMU_UFLAG_READ_LEN   0x2
+#define TCMU_UFLAG_KEEP_BUF   0x4
+	__u8 uflags;
+
+} __packed;
+
+#define TCMU_OP_MASK 0x7
+
+static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
+{
+	return len_op & TCMU_OP_MASK;
+}
+
+static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
+{
+	*len_op &= ~TCMU_OP_MASK;
+	*len_op |= (op & TCMU_OP_MASK);
+}
+
+static inline __u32 tcmu_hdr_get_len(__u32 len_op)
+{
+	return len_op & ~TCMU_OP_MASK;
+}
+
+static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
+{
+	*len_op &= TCMU_OP_MASK;
+	*len_op |= len;
+}
+
+/* Currently the same as SCSI_SENSE_BUFFERSIZE */
+#define TCMU_SENSE_BUFFERSIZE 96
+
+struct tcmu_cmd_entry {
+	struct tcmu_cmd_entry_hdr hdr;
+
+	union {
+		struct {
+			__u32 iov_cnt;
+			__u32 iov_bidi_cnt;
+			__u32 iov_dif_cnt;
+			__u64 cdb_off;
+			__u64 __pad1;
+			__u64 __pad2;
+			__DECLARE_FLEX_ARRAY(struct iovec, iov);
+		} req;
+		struct {
+			__u8 scsi_status;
+			__u8 __pad1;
+			__u16 __pad2;
+			__u32 read_len;
+			char sense_buffer[TCMU_SENSE_BUFFERSIZE];
+		} rsp;
+	};
+
+} __packed;
+
+struct tcmu_tmr_entry {
+	struct tcmu_cmd_entry_hdr hdr;
+
+#define TCMU_TMR_UNKNOWN		0
+#define TCMU_TMR_ABORT_TASK		1
+#define TCMU_TMR_ABORT_TASK_SET		2
+#define TCMU_TMR_CLEAR_ACA		3
+#define TCMU_TMR_CLEAR_TASK_SET		4
+#define TCMU_TMR_LUN_RESET		5
+#define TCMU_TMR_TARGET_WARM_RESET	6
+#define TCMU_TMR_TARGET_COLD_RESET	7
+/* Pseudo reset due to received PR OUT */
+#define TCMU_TMR_LUN_RESET_PRO		128
+	__u8 tmr_type;
+
+	__u8 __pad1;
+	__u16 __pad2;
+	__u32 cmd_cnt;
+	__u64 __pad3;
+	__u64 __pad4;
+	__u16 cmd_ids[];
+} __packed;
+
+#define TCMU_OP_ALIGN_SIZE sizeof(__u64)
+
+enum tcmu_genl_cmd {
+	TCMU_CMD_UNSPEC,
+	TCMU_CMD_ADDED_DEVICE,
+	TCMU_CMD_REMOVED_DEVICE,
+	TCMU_CMD_RECONFIG_DEVICE,
+	TCMU_CMD_ADDED_DEVICE_DONE,
+	TCMU_CMD_REMOVED_DEVICE_DONE,
+	TCMU_CMD_RECONFIG_DEVICE_DONE,
+	TCMU_CMD_SET_FEATURES,
+	__TCMU_CMD_MAX,
+};
+#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
+
+enum tcmu_genl_attr {
+	TCMU_ATTR_UNSPEC,
+	TCMU_ATTR_DEVICE,
+	TCMU_ATTR_MINOR,
+	TCMU_ATTR_PAD,
+	TCMU_ATTR_DEV_CFG,
+	TCMU_ATTR_DEV_SIZE,
+	TCMU_ATTR_WRITECACHE,
+	TCMU_ATTR_CMD_STATUS,
+	TCMU_ATTR_DEVICE_ID,
+	TCMU_ATTR_SUPP_KERN_CMD_REPLY,
+	__TCMU_ATTR_MAX,
+};
+#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
+
+#endif