Honor the configured ChatGPT origin in connector install URLs (#37338)

## What changed

- Build connector install URLs from `CODEX_APP_SERVER_CHATGPT_BASE_URL`, falling back to `https://chatgpt.com` when it is unset.
- Strip a trailing slash or `/backend-api` suffix before appending the `/apps/<slug>/<connector-id>` path.
- Add a test covering install URL generation with the configured origin.

GitOrigin-RevId: 854d15b7e322d2359684f974aaf27fe28205dd5a

codex-rs/connectors/src/lib.rs

@@ -480,8 +480,13 @@ fn directory_app_to_app_info(app: DirectoryApp) -> AppInfo {
 }
 
 fn connector_install_url(name: &str, connector_id: &str) -> String {
+    let chatgpt_base_url = std::env::var("CODEX_APP_SERVER_CHATGPT_BASE_URL")
+        .unwrap_or_else(|_| "https://chatgpt.com".to_string());
+    let chatgpt_origin = chatgpt_base_url
+        .trim_end_matches('/')
+        .trim_end_matches("/backend-api");
     let slug = connector_name_slug(name);
-    format!("https://chatgpt.com/apps/{slug}/{connector_id}")
+    format!("{chatgpt_origin}/apps/{slug}/{connector_id}")
 }
 
 fn connector_name_slug(name: &str) -> String {
@@ -569,6 +574,19 @@ mod tests {
         }
     }
 
+    #[test]
+    fn connector_install_url_uses_configured_origin() {
+        let chatgpt_base_url = std::env::var("CODEX_APP_SERVER_CHATGPT_BASE_URL")
+            .unwrap_or_else(|_| "https://chatgpt.com".to_string());
+        let chatgpt_origin = chatgpt_base_url
+            .trim_end_matches('/')
+            .trim_end_matches("/backend-api");
+        assert_eq!(
+            connector_install_url("Google Calendar", "calendar"),
+            format!("{chatgpt_origin}/apps/google-calendar/calendar"),
+        );
+    }
+
     #[test]
     fn directory_app_icon_assets_reach_app_info() -> anyhow::Result<()> {
         let response: DirectoryListResponse = serde_json::from_value(serde_json::json!({