Windows cursor grabbing is bugged

## Bevy version and features

0.18 main branch

## \[Optional\] Relevant system information

Windows 11

## What you did

Ran the attached code, hit the windows key to change focus, tried to move the cursor out of the window.

## What went wrong

If the debug print is showing that the cursor is not grabbed I expect the mouse to not act confined. It is not letting my mouse leave the window even though its not grabbed. I minimized the code for you.

## Additional information

```rs
use std::time::Duration;

use bevy::{
prelude::*,
window::{CursorGrabMode, CursorOptions, PrimaryWindow, WindowFocused},
};

fn main() {
App::new()
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window { ..default() }),
..default()
}))
.add_systems(Update, (print_cursor, handle_focus_change))
.run();
}

fn print_cursor(
primary_cursor_options: Single<&mut CursorOptions, With>,
mut time_since_last_print: Local,
time: Res,
) {
*time_since_last_print += time.delta();
if *time_since_last_print < Duration::from_secs(5) {
return;
}
println!("grabbed: {:?}", primary_cursor_options.grab_mode);
*time_since_last_print = Duration::ZERO;
}

fn handle_focus_change(
mut focus_events: MessageReader,
mut primary_cursor_options: Single<&mut CursorOptions, With>,
) {
for event in focus_events.read() {
if event.focused {
println!("gained focus");
primary_cursor_options.grab_mode = CursorGrabMode::Confined;
} else {
println!("lost focus");
primary_cursor_options.grab_mode = CursorGrabMode::None;
}
}
}

```

Start by running the attached minimal Rust reproduction on Windows 11 and tracing the handle_focus_change system together with CursorOptions and WindowFocused handling. Compare the reported grab_mode with the actual cursor behavior after focus is lost; done means CursorGrabMode::None allows the cursor to leave the window, with the behavior verified across the focus change shown.

Written by the indexing model from the issue text.