[tui] add optional details to TUI status header (#8293)

### What

Add optional `details` field to TUI's status indicator header. `details`
is shown under the header with text wrapping and a max height of 3
lines.

Duplicated changes to `tui2`.

### Why

Groundwork for displaying error details under `Reconnecting...` for
clarity with retryable errors.

Basic examples
<img width="1012" height="326" alt="image"
src="https://github.com/user-attachments/assets/dd751ceb-b179-4fb2-8fd1-e4784d6366fb"
/>

<img width="1526" height="358" alt="image"
src="https://github.com/user-attachments/assets/bbe466fc-faff-4a78-af7f-3073ccdd8e34"
/>

Truncation example
<img width="936" height="189" alt="image"
src="https://github.com/user-attachments/assets/f3f1b5dd-9050-438b-bb07-bd833c03e889"
/>

### Tests
Tested locally, added tests for truncation.

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

@@ -288,12 +288,13 @@ impl BottomPane {
         self.request_redraw();
     }
 
-    /// Update the animated header shown to the left of the brackets in the
-    /// status indicator (defaults to "Working"). No-ops if the status
-    /// indicator is not active.
-    pub(crate) fn update_status_header(&mut self, header: String) {
+    /// Update the status indicator header (defaults to "Working") and details below it.
+    ///
+    /// Passing `None` clears any existing details. No-ops if the status indicator is not active.
+    pub(crate) fn update_status(&mut self, header: String, details: Option<String>) {
         if let Some(status) = self.status.as_mut() {
             status.update_header(header);
+            status.update_details(details);
             self.request_redraw();
         }
     }