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）

markbase-core/src/download/storage.rs

@@ -0,0 +1,119 @@
+use serde::{Deserialize, Serialize};
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct FileInfo {
+    pub filename: String,
+    pub file_size: u64,
+    pub file_hash: Option<String>,
+    pub file_path: String,
+    pub relative_path: String,
+    pub upload_time: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct FileListResponse {
+    pub user_id: String,
+    pub base_path: String,
+    pub files: Vec<FileInfo>,
+    pub total_files: usize,
+    pub total_size: u64,
+}
+
+pub fn scan_uploaded_files(user_id: &str) -> FileListResponse {
+    let base_path = format!("/Users/accusys/Downloads/{}", user_id);
+    let path = Path::new(&base_path);
+    
+    let mut files = Vec::new();
+    let mut total_size = 0u64;
+    
+    if path.exists() {
+        scan_directory_recursive(path, path, &mut files, &mut total_size);
+    }
+    
+    FileListResponse {
+        user_id: user_id.to_string(),
+        base_path: base_path,
+        total_files: files.len(),
+        total_size,
+        files,
+    }
+}
+
+fn scan_directory_recursive(
+    base: &Path,
+    current: &Path,
+    files: &mut Vec<FileInfo>,
+    total_size: &mut u64,
+) {
+    if let Ok(entries) = std::fs::read_dir(current) {
+        for entry in entries.flatten() {
+            let path = entry.path();
+            
+            if path.is_file() {
+                let filename = path.file_name()
+                    .and_then(|n| n.to_str())
+                    .unwrap_or("unknown")
+                    .to_string();
+                
+                let file_size = entry.metadata()
+                    .map(|m| m.len())
+                    .unwrap_or(0);
+                
+                let relative_path = path.strip_prefix(base)
+                    .ok()
+                    .and_then(|p| p.to_str())
+                    .map(|s| s.to_string())
+                    .unwrap_or_else(|| filename.clone());
+                
+                let upload_time = entry.metadata()
+                    .ok()
+                    .and_then(|m| m.modified().ok())
+                    .and_then(|t| {
+                        let duration = t.duration_since(std::time::UNIX_EPOCH).ok()?;
+                        chrono::DateTime::from_timestamp(duration.as_secs() as i64, 0)
+                            .map(|dt| dt.format("%Y-%m-%dT%H:%M:%SZ").to_string())
+                    })
+                    .unwrap_or_else(|| chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string());
+                
+                let file_hash = if file_size > 0 {
+                    compute_file_hash(&path).ok()
+                } else {
+                    Some("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855".to_string())
+                };
+                
+                files.push(FileInfo {
+                    filename,
+                    file_size,
+                    file_hash,
+                    file_path: path.to_string_lossy().to_string(),
+                    relative_path,
+                    upload_time,
+                });
+                
+                *total_size += file_size;
+            } else if path.is_dir() {
+                scan_directory_recursive(base, &path, files, total_size);
+            }
+        }
+    }
+}
+
+pub fn compute_file_hash(path: &Path) -> Result<String, std::io::Error> {
+    use sha2::{Digest, Sha256};
+    use std::io::Read;
+    
+    let mut file = std::fs::File::open(path)?;
+    let mut hasher = Sha256::new();
+    let mut buffer = [0u8; 8192];
+    
+    loop {
+        let bytes_read = file.read(&mut buffer)?;
+        if bytes_read == 0 {
+            break;
+        }
+        hasher.update(&buffer[..bytes_read]);
+    }
+    
+    Ok(format!("{:x}", hasher.finalize()))
+}