`NonSend<WinitWindows>` failed system-param validation on the
first few frames before `WinitWindows` was populated, panicking
the Update system before any logic could run. Bevy 0.18's
stricter validation panics rather than skips when a non-send
resource is absent, with an error message spelling out the fix:
*"wrap the parameter in `Option<T>` and handle `None` when it
happens."*
Wraps `winit_windows` as `Option<NonSend<WinitWindows>>` and
early-returns on `None`, mirroring the same lifecycle handling
already applied to `winit_windows.get_window(primary_entity)` —
both fail in the same window of frames before winit's `Resumed`
event fires.
Repro from the user's `cargo run` log:
```
thread 'Compute Task Pool (2)' panicked at .../bevy_ecs-0.18.1/src/error/handler.rs:125:1:
Encountered an error in system ...: Parameter ... failed validation:
Non-send resource does not exist
```
Workspace clippy + cargo test --workspace clean, 1185 passing.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
funman300
716a025352