feat: add registry config, image upload/download, and OCI format support

Backend:
- Add registry_address configuration API (GET/POST)
- Add tar image upload with OCI and Docker format support
- Add image download with streaming optimization
- Fix blob download using c.Send (Fiber v3 SendStream bug)
- Add registry_address prefix stripping for all OCI v2 endpoints
- Add AGENTS.md for project documentation

Frontend:
- Add settings store with Snackbar notifications
- Add image upload dialog with progress bar
- Add download state tracking with multi-stage feedback
- Replace alert() with MUI Snackbar messages
- Display image names without registry_address prefix

🤖 Generated with [Qoder](https://qoder.com)

pkg/tool/file.go

@@ -0,0 +1,157 @@
+package tool
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// FileMD5 calculate file md5
+//   - if file not exist, return ""
+//   - if _path is dir, return ""
+func FileMD5(_path string) string {
+	// 检查文件是否存在
+	fileInfo, err := os.Stat(_path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return ""
+		}
+		// 其他错误也返回空字符串
+		return ""
+	}
+
+	// 检查是否是目录
+	if fileInfo.IsDir() {
+		return ""
+	}
+
+	// 打开文件
+	file, err := os.Open(_path)
+	if err != nil {
+		return ""
+	}
+	defer file.Close()
+
+	// 创建MD5哈希计算器
+	hash := md5.New()
+
+	// 将文件内容复制到哈希计算器
+	if _, err := io.Copy(hash, file); err != nil {
+		return ""
+	}
+
+	// 计算并返回MD5哈希值（十六进制字符串）
+	return fmt.Sprintf("%x", hash.Sum(nil))
+}
+
+// CopyFile copies a file from src to dst.
+// Returns an error if source/destination are the same, source isn't a regular file,
+// or any step in the copy process fails.
+func CopyFile(src, dst string) error {
+	// Open source file
+	srcFile, err := os.Open(src)
+	if err != nil {
+		return fmt.Errorf("failed to open source: %w", err)
+	}
+	defer srcFile.Close()
+
+	// Get source file metadata
+	srcInfo, err := srcFile.Stat()
+	if err != nil {
+		return fmt.Errorf("failed to get source info: %w", err)
+	}
+
+	// Verify source is a regular file
+	if !srcInfo.Mode().IsRegular() {
+		return fmt.Errorf("source is not a regular file")
+	}
+
+	// Check if source and destination are the same file
+	if same, err := sameFile(src, dst, srcInfo); same {
+		return fmt.Errorf("source and destination are the same file")
+	} else if err != nil {
+		return err
+	}
+
+	// Create destination directory structure
+	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		return fmt.Errorf("failed to create destination directory: %w", err)
+	}
+
+	// Create destination file with source permissions
+	dstFile, err := os.OpenFile(dst, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, srcInfo.Mode())
+	if err != nil {
+		return fmt.Errorf("failed to create destination: %w", err)
+	}
+
+	// Copy contents and handle destination close errors
+	_, err = io.Copy(dstFile, srcFile)
+	if closeErr := dstFile.Close(); closeErr != nil && err == nil {
+		err = fmt.Errorf("failed to close destination: %w", closeErr)
+	}
+	if err != nil {
+		return fmt.Errorf("copy failed: %w", err)
+	}
+
+	return nil
+}
+
+// sameFile checks if src and dst refer to the same file using device/inode numbers
+func sameFile(src, dst string, srcInfo os.FileInfo) (bool, error) {
+	dstInfo, err := os.Stat(dst)
+	if os.IsNotExist(err) {
+		return false, nil // Destination doesn't exist
+	}
+	if err != nil {
+		return false, err // Other errors
+	}
+	return os.SameFile(srcInfo, dstInfo), nil
+}
+
+func CopyDir(src, dst string) error {
+	// todo: copy src dir to dst dir recursively
+	// if dst is not exist, create it
+	// if file exist, overwrite it
+	srcInfo, err := os.Stat(src)
+	if err != nil {
+		return fmt.Errorf("stat src dir failed: %w", err)
+	}
+	if !srcInfo.IsDir() {
+		return fmt.Errorf("source is not a directory")
+	}
+
+	// Create destination directory if it does not exist
+	if err := os.MkdirAll(dst, srcInfo.Mode()); err != nil {
+		return fmt.Errorf("failed to create destination directory: %w", err)
+	}
+
+	entries, err := os.ReadDir(src)
+	if err != nil {
+		return fmt.Errorf("failed to read source directory: %w", err)
+	}
+
+	for _, entry := range entries {
+		srcPath := filepath.Join(src, entry.Name())
+		dstPath := filepath.Join(dst, entry.Name())
+
+		info, err := entry.Info()
+		if err != nil {
+			return fmt.Errorf("failed to get info for %s: %w", srcPath, err)
+		}
+
+		if info.IsDir() {
+			// Recursively copy subdirectory
+			if err := CopyDir(srcPath, dstPath); err != nil {
+				return err
+			}
+		} else {
+			// Copy file, overwrite if exists
+			if err := CopyFile(srcPath, dstPath); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}