[Feature Request] Add Screener support

Hey CLI doesn't currently expose the Screener.

For automated triage workflows, being able to list pending Screener items and approve/deny them via CLI would be really useful.

Proposed commands:
```
hey screener                    # list pending senders
hey screener approve <id>       # screen in
hey screener deny <id>          # screen out
```

Love the CLI so far.