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"
/>

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

codex-rs/Cargo.toml

@@ -150,6 +150,7 @@ pretty_assertions = "1.4.1"
 pulldown-cmark = "0.10"
 rand = "0.9"
 ratatui = "0.29.0"
+ratatui-macros = "0.6.0"
 regex-lite = "0.1.7"
 reqwest = "0.12"
 rmcp = { version = "0.8.0", default-features = false }