syntax-highlight bash lines (#3142)

i'm not yet convinced i have the best heuristics for what to highlight,
but this feels like a useful step towards something a bit easier to
read, esp. when the model is producing large commands.

<img width="669" height="589" alt="Screenshot 2025-09-03 at 8 21 56 PM"
src="https://github.com/user-attachments/assets/b9cbcc43-80e8-4d41-93c8-daa74b84b331"
/>

also a fairly significant refactor of our line wrapping logic.

codex-rs/tui/src/pager_overlay.rs

@@ -1,7 +1,7 @@
 use std::io::Result;
 use std::time::Duration;
 
-use crate::insert_history;
+use crate::render::line_utils::push_owned_lines;
 use crate::tui;
 use crate::tui::TuiEvent;
 use crossterm::event::KeyCode;
@@ -287,9 +287,9 @@ impl PagerView {
         let mut wrapped: Vec<Line<'static>> = Vec::new();
         let mut src_idx: Vec<usize> = Vec::new();
         for (i, line) in self.lines.iter().enumerate() {
-            let ws = insert_history::word_wrap_lines(std::slice::from_ref(line), width);
+            let ws = crate::wrapping::word_wrap_line(line, width as usize);
             src_idx.extend(std::iter::repeat_n(i, ws.len()));
-            wrapped.extend(ws);
+            push_owned_lines(&ws, &mut wrapped);
         }
         self.wrap_cache = Some(WrapCache {
             width,