allow optional -w diff when presenting changes

Question

### What version of Codex CLI is running?

5.4

### What subscription do you have?

chatgpt plus?

### Which model were you using?

5.4 medium

### What platform is your computer?

linux

### What terminal emulator and version are you using (if applicable)?

mac terminal

### Codex doctor report

```json

```

### What issue are you seeing?

suggestion: there should be an option so when diffs are being shown by codex they could include -w (ignore whitespace)

### What steps can reproduce the bug