Add text element metadata to types (#9235)

Initial type tweaking PR to make the diff of
https://github.com/openai/codex/pull/9116 smaller

This should not change any behavior, just adds some fields to types

codex-rs/otel/src/traces/otel_manager.rs

@@ -324,7 +324,7 @@ impl OtelManager {
         let prompt = items
             .iter()
             .flat_map(|item| match item {
-                UserInput::Text { text } => Some(text.as_str()),
+                UserInput::Text { text, .. } => Some(text.as_str()),
                 _ => None,
             })
             .collect::<String>();