tui: coalesce command output; show unabridged commands in transcript (#2590)

https://github.com/user-attachments/assets/effec7c7-732a-4b61-a2ae-3cb297b6b19b

codex-rs/protocol/src/protocol.rs

@@ -674,6 +674,8 @@ pub struct ExecCommandEndEvent {
     pub exit_code: i32,
     /// The duration of the command execution.
     pub duration: Duration,
+    /// Formatted output from the command, as seen by the model.
+    pub formatted_output: String,
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize)]