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/chat_composer.rs

@@ -22,11 +22,6 @@ use crate::app_event::AppEvent;
 use crate::app_event_sender::AppEventSender;
 use codex_file_search::FileMatch;
 
-/// Minimum number of visible text rows inside the textarea.
-const MIN_TEXTAREA_ROWS: usize = 1;
-/// Rows consumed by the border.
-const BORDER_LINES: u16 = 2;
-
 const BASE_PLACEHOLDER_TEXT: &str = "send a message";
 /// If the pasted content exceeds this number of characters, replace it with a
 /// placeholder in the UI.
@@ -609,17 +604,6 @@ impl ChatComposer<'_> {
         self.dismissed_file_popup_token = None;
     }
 
-    pub fn calculate_required_height(&self, area: &Rect) -> u16 {
-        let rows = self.textarea.lines().len().max(MIN_TEXTAREA_ROWS);
-        let num_popup_rows = match &self.active_popup {
-            ActivePopup::Command(popup) => popup.calculate_required_height(area),
-            ActivePopup::File(popup) => popup.calculate_required_height(area),
-            ActivePopup::None => 0,
-        };
-
-        rows as u16 + BORDER_LINES + num_popup_rows
-    }
-
     fn update_border(&mut self, has_focus: bool) {
         struct BlockState {
             right_title: Line<'static>,