Function default_user_agent 

pub fn default_user_agent(profile: &TlsProfile) -> &'static str

Return a User-Agent string that matches the given TLS profile’s browser.

Anti-bot systems cross-reference the User-Agent header against the TLS fingerprint. Sending a Chrome TLS profile with a Firefox User-Agent is a strong detection signal.

Matching logic

Profile name contains	User-Agent
"Chrome"	Chrome 131 on Windows 10
"Firefox"	Firefox 133 on Windows 10
"Safari"	Safari 18 on macOS 14.7
"Edge"	Edge 131 on Windows 10
(other)	Chrome 131 on Windows 10 (safe fallback)