detect terminal and include in request headers (#2437)

This adds the terminal version to the UA header.

codex-rs/core/src/user_agent.rs

@@ -4,11 +4,12 @@ pub fn get_codex_user_agent(originator: Option<&str>) -> String {
     let build_version = env!("CARGO_PKG_VERSION");
     let os_info = os_info::get();
     format!(
-        "{}/{build_version} ({} {}; {})",
+        "{}/{build_version} ({} {}; {}) {}",
         originator.unwrap_or(DEFAULT_ORIGINATOR),
         os_info.os_type(),
         os_info.version(),
         os_info.architecture().unwrap_or("unknown"),
+        crate::terminal::user_agent()
     )
 }
 
@@ -27,9 +28,10 @@ mod tests {
     fn test_macos() {
         use regex_lite::Regex;
         let user_agent = get_codex_user_agent(None);
-        let re =
-            Regex::new(r"^codex_cli_rs/\d+\.\d+\.\d+ \(Mac OS \d+\.\d+\.\d+; (x86_64|arm64)\)$")
-                .unwrap();
+        let re = Regex::new(
+            r"^codex_cli_rs/\d+\.\d+\.\d+ \(Mac OS \d+\.\d+\.\d+; (x86_64|arm64)\) (\S+)$",
+        )
+        .unwrap();
         assert!(re.is_match(&user_agent));
     }
 }