Add a common way to create HTTP client (#3110)

Ensure User-Agent and originator are always sent.

codex-rs/cli/src/login.rs

@@ -60,7 +60,11 @@ pub async fn run_login_with_api_key(
 pub async fn run_login_status(cli_config_overrides: CliConfigOverrides) -> ! {
     let config = load_config_or_exit(cli_config_overrides);
 
-    match CodexAuth::from_codex_home(&config.codex_home, config.preferred_auth_method) {
+    match CodexAuth::from_codex_home(
+        &config.codex_home,
+        config.preferred_auth_method,
+        &config.responses_originator_header,
+    ) {
         Ok(Some(auth)) => match auth.mode {
             AuthMode::ApiKey => match auth.get_token().await {
                 Ok(api_key) => {