Bug in zsh completion?

I think that there may be a bug in the completion file for zsh. Here's how to trigger it.

```shell
passage -
```

After tabbing at that position, the cursor moves one character left (!), so that the next character you enter is placed **before** `-` rather than after it.

I am not especially comfortable with zsh completions, but I have a version that works for me [in this gist](https://gist.github.com/telemachus/e6d3eb61905e1cfa9e36d2a8e47ab228). (Briefly: I think the problem is that the current completion [mixes its handling of command-level flags and subcommands](https://github.com/FiloSottile/passage/blob/main/src/completion/pass.zsh-completion#L85-L106).) I'm happy to submit a PR, but I'm hoping to see (1) if other people have experienced the same problem and (2) if my solution looks good to people who know more about zsh completions than me.

Reproduce the issue with `passage -` and inspect `src/completion/pass.zsh-completion`, especially lines 85-106 where command-level flags and subcommands are handled. Compare the current completion with the linked gist; done means completing at that position no longer moves the cursor left and subsequent input appears after `-`.

Written by the indexing model from the issue text.