`rtk git commit -am message` fails

```
❯ git commit -am tmp
On branch foo
nothing to commit, working tree clean
```

```
❯ rtk git commit -am tmp
error: unexpected argument '-a' found

Usage: rtk git commit [OPTIONS]

For more information, try '--help'.
```

Claude handles this adequately, by running `git add ... && git commit -m ...`, but it would be better if rtk could cope.