[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/status/rate_limits.rs

@@ -1,4 +1,5 @@
 use crate::chatwidget::get_limits_duration;
+use crate::text_formatting::capitalize_first;
 
 use super::helpers::format_reset_timestamp;
 use chrono::DateTime;
@@ -221,15 +222,3 @@ fn format_credit_balance(raw: &str) -> Option<String> {
 
     None
 }
-
-fn capitalize_first(label: &str) -> String {
-    let mut chars = label.chars();
-    match chars.next() {
-        Some(first) => {
-            let mut capitalized = first.to_uppercase().collect::<String>();
-            capitalized.push_str(chars.as_str());
-            capitalized
-        }
-        None => String::new(),
-    }
-}