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）

docs/EMPTY_DIRECTORY_GUIDE.md

@@ -0,0 +1,127 @@
+# Empty Directory Upload Guide
+
+## Problem
+webkitdirectory浏览器行为限制：**无法上传空目录**
+
+浏览器只选择**文件**，空目录不会被包含在fileInput.files中。
+
+## Solutions
+
+### Solution 1: Empty File Marker (Recommended)
+
+**Add `.keep` or `.gitkeep` in every empty directory:**
+
+```bash
+# Before upload, add empty files in empty directories
+find /path/to/upload -type d -empty -exec touch {}/.keep \;
+
+# This ensures all directories will be uploaded
+```
+
+**Example structure:**
+```
+ExaSAN-DAS/
+├── ExaSAN-Carry-12/
+│   ├── System_Code.bin
+│   └── Boot_Code.bin
+├── EmptyFolder1/
+│   └── .keep  (0 bytes, ensures directory upload)
+└── EmptyFolder2/
+    ├── SubEmptyFolder/
+    │   └── .keep  (nested empty directory)
+    └── .keep
+```
+
+### Solution 2: Manual Creation
+
+**Upload files first, then create empty directories:**
+
+```bash
+# 1. Upload all files with webkitdirectory
+# 2. Find empty directories in source
+find /path/to/source -type d -empty > empty_dirs.txt
+
+# 3. Create in destination
+while read dir; do
+    relative=${dir#/path/to/source/}
+    mkdir -p "/Users/accusys/Downloads/accusys/$relative"
+done < empty_dirs.txt
+```
+
+### Solution 3: Script Automation
+
+**Automated script for empty directory handling:**
+
+```bash
+#!/bin/bash
+# prepare_upload.sh - Prepare directory for upload
+
+SOURCE_DIR="$1"
+
+echo "=== Preparing upload for $SOURCE_DIR ==="
+
+# Add .keep in all empty directories
+find "$SOURCE_DIR" -type d -empty | while read dir; do
+    touch "$dir/.keep"
+    echo "Added .keep in: $dir"
+done
+
+echo "=== Preparation complete ==="
+echo "Empty directories now have .keep files"
+echo "Ready for webkitdirectory upload"
+```
+
+**Usage:**
+```bash
+# Prepare before upload
+bash scripts/prepare_upload.sh /path/to/ExaSAN-DAS
+
+# Then upload using webkitdirectory
+# All empty directories will be uploaded with .keep files
+```
+
+## MarkBase Upload Service Status
+
+**Current Support:**
+- ✅ Empty files (0 bytes): `.localized`, `.keep`, `.gitkeep`
+- ✅ Subdirectory creation: Automatic `create_dir_all(parent)`
+- ✅ Multi-level paths: `subfolder/deeper/file.txt`
+- ❌ Empty directories: Browser limitation (use `.keep` workaround)
+
+## Best Practice
+
+**For 290 files upload:**
+
+1. **Prepare source directory:**
+   ```bash
+   bash scripts/prepare_upload.sh /path/to/AccuSys Downloads
+   ```
+
+2. **Upload via webkitdirectory:**
+   - Open https://download.accusys.ddns.net/upload
+   - Select entire folder
+   - All files + `.keep` files uploaded
+   - Directory structure preserved
+
+3. **Verify uploaded structure:**
+   ```bash
+   find /Users/accusys/Downloads/accusys -type d
+   ```
+
+## Implementation Notes
+
+**MarkBase upload_unlimited API:**
+- Removed `file_size == 0` validation (server.rs:1145)
+- Allows empty files: `.localized`, `.keep`, `.DS_Store`
+- Automatic subdirectory creation: `create_dir_all(parent)`
+- SHA256 checksum for empty files: `e3b0c44298fc1c...`
+
+**Technical limitation:**
+- webkitdirectory是HTML5标准限制
+- 无法通过服务器端修改绕过
+- 只能通过`.keep`文件 workaround
+
+---
+
+**Last Updated: 2026-06-09**
+**Version: 2.6 (Empty File + Empty Directory Support)**