bug: fix model save (#3525)

Fix those 2 behaviors:
1. The model does not get saved if we don't CTRL + S
2. The reasoning effort get saved

codex-rs/tui/src/chatwidget.rs

@@ -1451,4 +1451,4 @@ fn extract_first_bold(s: &str) -> Option<String> {
 }
 
 #[cfg(test)]
-mod tests;
+pub(crate) mod tests;