Easily Selectable History (#1672)

This update replaces the previous ratatui history widget with an
append-only log so that the terminal can handle text selection and
scrolling. It also disables streaming responses, which we'll do our best
to bring back in a later PR. It also adds a small summary of token use
after the TUI exits.

codex-rs/tui/src/bottom_pane/bottom_pane_view.rs

@@ -22,9 +22,6 @@ pub(crate) trait BottomPaneView<'a> {
         false
     }
 
-    /// Height required to render the view.
-    fn calculate_required_height(&self, area: &Rect) -> u16;
-
     /// Render the view: this will be displayed in place of the composer.
     fn render(&self, area: Rect, buf: &mut Buffer);