Function discover_chrome 

pub async fn discover_chrome(
    host: &str,
    port: u16,
) -> Result<(String, u16), ChromeError>

Attempt to discover a running Chrome instance.

Tries DevToolsActivePort file first, then falls back to the given host/port. Returns the WebSocket URL and port on success.

Errors

Returns ChromeError::NotRunning if no Chrome instance can be discovered.