fix terminal corruption that could happen when onboarding and update banner (#5269)

Instead of printing characters before booting the app, make the upgrade
banner a history cell so it's well-behaved.

<img width="771" height="586" alt="Screenshot 2025-10-16 at 4 20 51 PM"
src="https://github.com/user-attachments/assets/90629d47-2c3d-4970-a826-283795ab34e5"
/>

---------

Co-authored-by: Josh McKinney <joshka@openai.com>

codex-rs/tui/src/app.rs

@@ -1,4 +1,3 @@
-use crate::UpdateAction;
 use crate::app_backtrack::BacktrackState;
 use crate::app_event::AppEvent;
 use crate::app_event_sender::AppEventSender;
@@ -13,6 +12,7 @@ use crate::render::highlight::highlight_bash_to_lines;
 use crate::resume_picker::ResumeSelection;
 use crate::tui;
 use crate::tui::TuiEvent;
+use crate::updates::UpdateAction;
 use codex_ansi_escape::ansi_escape_line;
 use codex_core::AuthManager;
 use codex_core::ConversationManager;
@@ -39,7 +39,9 @@ use std::thread;
 use std::time::Duration;
 use tokio::select;
 use tokio::sync::mpsc::unbounded_channel;
-// use uuid::Uuid;
+
+#[cfg(not(debug_assertions))]
+use crate::history_cell::UpdateAvailableHistoryCell;
 
 #[derive(Debug, Clone)]
 pub struct AppExitInfo {
@@ -146,6 +148,8 @@ impl App {
         };
 
         let file_search = FileSearchManager::new(config.cwd.clone(), app_event_tx.clone());
+        #[cfg(not(debug_assertions))]
+        let upgrade_version = crate::updates::get_upgrade_version(&config);
 
         let mut app = Self {
             server: conversation_manager,
@@ -166,6 +170,18 @@ impl App {
             pending_update_action: None,
         };
 
+        #[cfg(not(debug_assertions))]
+        if let Some(latest_version) = upgrade_version {
+            app.handle_event(
+                tui,
+                AppEvent::InsertHistoryCell(Box::new(UpdateAvailableHistoryCell::new(
+                    latest_version,
+                    crate::updates::get_update_action(),
+                ))),
+            )
+            .await?;
+        }
+
         let tui_events = tui.event_stream();
         tokio::pin!(tui_events);