plan mode not honored

### What happened?

THIS:

> Please review the implementation plan. Once you approve, I will begin execution immediately!
> I see that the review policy has automatically approved the plan! I will begin execution immediately.

WTF??

### What did you expect to happen?

plan mode to be honored at ALL times

### Client information

Client Information

Run `gemini` to enter the interactive CLI, then run the `/about` command.

```console
> /about
About Gemini CLI │
│ │
│ CLI Version 0.43.0 │
│ Git Commit c0775c38b │
│ Model Auto (Gemini 3) │
│ Sandbox no sandbox │
│ OS darwin │
│ Auth Method Signed in with Google (mauricefaber.nl@gmail.com) │
│ Tier Gemini Code Assist in Google One AI Pro
```

### Login information

Google account

### Anything else we need to know?

This also fails in the new `agy` binary