Function is_valid_daemon_id 

pub fn is_valid_daemon_id(id: &str) -> bool

Validates a daemon ID to ensure it’s safe for use in file paths and IPC.

A valid daemon ID:

• Is not empty
• Does not contain path separators (/ or \)
• Does not contain parent directory references (..)
• Does not contain spaces
• Is not . (current directory)
• Contains only printable ASCII characters

This validation prevents path traversal attacks when daemon IDs are used to construct log file paths or other filesystem operations.