hide CoT by default; show headers in status indicator (#2316)

Plan is for full CoT summaries to be visible in a "transcript view" when
we implement that, but for now they're hidden.


https://github.com/user-attachments/assets/e8a1b0ef-8f2a-48ff-9625-9c3c67d92cdb

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

@@ -28,6 +28,11 @@ pub(crate) trait BottomPaneView {
     /// Render the view: this will be displayed in place of the composer.
     fn render(&self, area: Rect, buf: &mut Buffer);
 
+    /// Update the status indicator animated header. Default no-op.
+    fn update_status_header(&mut self, _header: String) {
+        // no-op
+    }
+
     /// Called when task completes to check if the view should be hidden.
     fn should_hide_when_task_is_done(&mut self) -> bool {
         false

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

@@ -182,6 +182,17 @@ impl BottomPane {
         self.request_redraw();
     }
 
+    /// Update the animated header shown to the left of the brackets in the
+    /// status indicator (defaults to "Working"). This will update the active
+    /// StatusIndicatorView if present; otherwise, if a live overlay is active,
+    /// it will update that. If neither is present, this call is a no-op.
+    pub(crate) fn update_status_header(&mut self, header: String) {
+        if let Some(view) = self.active_view.as_mut() {
+            view.update_status_header(header.clone());
+            self.request_redraw();
+        }
+    }
+
     pub(crate) fn show_ctrl_c_quit_hint(&mut self) {
         self.ctrl_c_quit_hint = true;
         self.composer

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

@@ -24,9 +24,17 @@ impl StatusIndicatorView {
     pub fn update_text(&mut self, text: String) {
         self.view.update_text(text);
     }
+
+    pub fn update_header(&mut self, header: String) {
+        self.view.update_header(header);
+    }
 }
 
 impl BottomPaneView for StatusIndicatorView {
+    fn update_status_header(&mut self, header: String) {
+        self.update_header(header);
+    }
+
     fn should_hide_when_task_is_done(&mut self) -> bool {
         true
     }