重构：文件系统模块化架构，优化应用启动流程

internal/filesystem/errors.go

@@ -0,0 +1,130 @@
+package filesystem
+
+import (
+	"fmt"
+	"runtime"
+)
+
+// ErrorCode 错误码类型
+type ErrorCode string
+
+const (
+	// 通用错误
+	ErrCodeGeneral     ErrorCode = "GENERAL_ERROR"
+	ErrCodeInvalid     ErrorCode = "INVALID_ARGUMENT"
+	ErrCodeNotFound    ErrorCode = "NOT_FOUND"
+	ErrCodePermission  ErrorCode = "PERMISSION_DENIED"
+	ErrCodeIO          ErrorCode = "IO_ERROR"
+
+	// 路径相关错误
+	ErrCodePathTraversal  ErrorCode = "PATH_TRAVERSAL"
+	ErrCodeInvalidPath    ErrorCode = "INVALID_PATH"
+	ErrCodeSensitivePath  ErrorCode = "SENSITIVE_PATH"
+
+	// 文件操作错误
+	ErrCodeFileNotFound    ErrorCode = "FILE_NOT_FOUND"
+	ErrCodeFileExists      ErrorCode = "FILE_EXISTS"
+	ErrCodeDirectoryNotEmpty ErrorCode = "DIRECTORY_NOT_EMPTY"
+
+	// 安全相关错误
+	ErrCodeSecurityViolation ErrorCode = "SECURITY_VIOLATION"
+	ErrCodeSizeLimit        ErrorCode = "SIZE_LIMIT_EXCEEDED"
+	ErrCodeFileLocked      ErrorCode = "FILE_LOCKED"
+
+	// ZIP相关错误
+	ErrCodeZipInvalid    ErrorCode = "ZIP_INVALID"
+	ErrCodeZipBomb       ErrorCode = "ZIP_BOMB"
+	ErrCodeZipExtract    ErrorCode = "ZIP_EXTRACT_FAILED"
+)
+
+// FileError 文件系统专用错误类型
+// 包含详细的错误上下文信息，便于调试和用户提示
+type FileNotFoundError struct {
+	Path string
+	Err  error
+}
+
+func (e *FileNotFoundError) Error() string {
+	return fmt.Sprintf("文件不存在: %s", e.Path)
+}
+
+func (e *FileNotFoundError) Unwrap() error {
+	return e.Err
+}
+
+// PathValidationError 路径验证错误
+type PathValidationError struct {
+	Path        string
+	Reason      string
+	IsSensitive bool
+}
+
+func (e *PathValidationError) Error() string {
+	return fmt.Sprintf("路径验证失败: %s - %s", e.Path, e.Reason)
+}
+
+// SecurityViolationError 安全违规错误
+type SecurityViolationError struct {
+	Path       string
+	Violation  string
+	Suggestion string
+}
+
+func (e *SecurityViolationError) Error() string {
+	msg := fmt.Sprintf("安全违规: %s - %s", e.Path, e.Violation)
+	if e.Suggestion != "" {
+		msg += fmt.Sprintf("\n建议: %s", e.Suggestion)
+	}
+	return msg
+}
+
+// SizeLimitError 大小限制错误
+type SizeLimitError struct {
+	Path        string
+	ActualSize  int64
+	MaxSize     int64
+	SizeType    string // "file" or "directory"
+}
+
+func (e *SizeLimitError) Error() string {
+	return fmt.Sprintf("%s大小超限: %s (实际: %.2f GB, 限制: %.2f GB)",
+		e.SizeType, e.Path,
+		float64(e.ActualSize)/(1024*1024*1024),
+		float64(e.MaxSize)/(1024*1024*1024),
+	)
+}
+
+// FileLockedError 文件锁定错误
+type FileLockedError struct {
+	Path        string
+	ProcessInfo string
+}
+
+func (e *FileLockedError) Error() string {
+	msg := fmt.Sprintf("文件被占用: %s", e.Path)
+	if e.ProcessInfo != "" {
+		msg += fmt.Sprintf("\n占用程序: %s", e.ProcessInfo)
+	}
+	return msg
+}
+
+// WrapError 错误包装函数
+// 添加上下文信息到错误中
+func WrapError(operation string, path string, err error) error {
+	return fmt.Errorf("%s 失败: %s - %w", operation, path, err)
+}
+
+// WrapErrorf 格式化错误包装
+func WrapErrorf(format string, args ...interface{}) error {
+	return fmt.Errorf(format, args...)
+}
+
+// GetStackTrace 获取堆栈跟踪（用于调试）
+func GetStackTrace(skip int) string {
+	buf := make([]byte, 4096)
+	n := runtime.Stack(buf, false)
+	if n > 0 {
+		return string(buf[:n])
+	}
+	return ""
+}