Keep interrupted prompts in conversation history (#33198)

## What changed

- Leave an output-free interrupted prompt in the transcript and open a blank
  composer for the user's next instruction.
- Use the normal interruption notice for both `Esc` and `Ctrl-C` interrupts.
- Track safety-buffering prompts separately so failed retries can still restore
  the prompt, including after switching between threads.

## Testing

- Cover output-free `Esc` and `Ctrl-C` interrupts, failed safety-buffer retries,
  and restoration of safety-buffer state from thread snapshots.

GitOrigin-RevId: 30b368d00dfdb981d06d4c95ce3f252389b7917c

codex-rs/tui/src/chatwidget/command_lifecycle.rs

@@ -240,7 +240,6 @@ impl ChatWidget {
     }
 
     pub(crate) fn handle_command_execution_started_now(&mut self, item: ThreadItem) {
-        self.record_visible_turn_activity();
         let ThreadItem::CommandExecution {
             id,
             command,