logging

type Config struct {
	Level      string // Log level: debug, info, warn, error
	FilePath   string // Path to log file (empty = stderr only)
	MaxSizeMB  int    // Max size in MB before rotation
	MaxBackups int    // Max number of old log files to retain
	MaxAgeDays int    // Max age in days to retain old log files
	Compress   bool   // Whether to compress rotated files
}