[BUG] floating window does not disappear when diff view is shown

## Bug Description

With `terminal.snacks_win_opts.position` is set to `float`, the floating window does not disappear when a diff view is opened. Instead, the diff view is visible and has cursor focus. Calling `ClaudeCodeFocus` will switch focus to the open floating window. Calling it again will make the window disappear and switch to the diff view. However, this is a very cumbersome workaround.

My config:
```
{
terminal_cmd = "~/.claude/local/claude",
diff_opts = {
keep_terminal_focus = false,
},
terminal = {
snacks_win_opts = {
position="float",
width=0.9,
height=0.9,
backdrop={
bg="blue",
blend=90,
},
keys = {
claude_hide = {
toggle_key,
function(self)
self:hide()
end,
mode="t",
desc="Hide",
}
},
}
}
}

```

## To Reproduce

Steps to reproduce the behavior:

1. Open a file and launch Claude Code by calling `ClaudeCodeFocus`.
2. Ask Claude to produce a change to the code.
3. Observe that the diff view opens, with the cursor on it, but the floating window is still visible mostly obscuring it.

## Expected Behavior

The floating window should disappear when the diff view opens.

## Environment

- Neovim version: 0.9.5 (0.9.5-6ubuntu2)
- Claude Code CLI version: 2.1.19
- OS: Ubuntu 24.04.3 LTS
- Plugin version: main (93f8e48)
- Snacks version: 2.27.0

L’issue mentionne ClaudeCodeFocus et le flux de diff-view ; reproduisez-le avec terminal.snacks_win_opts.position défini sur float et diff_opts.keep_terminal_focus=false. Suivez la gestion du focus et des fenêtres autour de ClaudeCodeFocus et de l’ouverture du diff, puis vérifiez que l’ouverture du diff masque la fenêtre flottante sans second appel de focus.

Rédigé par le modèle d'indexation à partir du texte de l'issue.