fix(tui): propagate errors in insert_history_lines_to_writer (#4266)

## What?
Fixed error handling in `insert_history_lines_to_writer` where all
terminal operations were silently ignoring errors via `.ok()`.

  ## Why?
Silent I/O failures could leave the terminal in an inconsistent state
(e.g., scroll region not reset) with no way to debug. This violates Rust
error handling best practices.

  ## How?
  - Changed function signature to return `io::Result<()>`
  - Replaced all `.ok()` calls with `?` operator to propagate errors
- Added `tracing::warn!` in wrapper function for backward compatibility
  - Updated 15 test call sites to handle Result  with `.expect()`

  ## Testing
  - ✅ Pass all tests

  ## Type of Change
  - [x] Bug fix (non-breaking change)

---------

Signed-off-by: Huaiwu Li <lhwzds@gmail.com>
Co-authored-by: Eric Traut <etraut@openai.com>

codex-rs/tui/src/tui.rs

@@ -548,7 +548,7 @@ impl Tui {
                 crate::insert_history::insert_history_lines(
                     terminal,
                     self.pending_history_lines.clone(),
-                );
+                )?;
                 self.pending_history_lines.clear();
             }
             // Update the y position for suspending so Ctrl-Z can place the cursor correctly.