[Xcode 26.4] Release build emits reorder-init-list and symbol-less object warnings

## Summary

A clean iOS Release simulator build with react-native-safe-area-context 5.8.0 emits two `-Wreorder-init-list` diagnostics per architecture from `RNCSafeAreaProviderComponentView.mm`. Under Xcode 26.4.1, libtool also warns that `RNCSafeAreaViewState.o` has no symbols when its implementation is compiled out for the selected platform/configuration.

## Environment

- react-native-safe-area-context: 5.8.0
- React Native: 0.86.0
- Expo: 57.0.4
- Xcode: 26.4.1
- SDK: iOS 26.2 simulator
- configuration: Release, new architecture

## Diagnostics

```text
RNCSafeAreaProviderComponentView.mm:110:27: warning: ISO C++ requires field designators to be specified in declaration order; field left will be initialized after field bottom [-Wreorder-init-list]
RNCSafeAreaProviderComponentView.mm:111:26: warning: ISO C++ requires field designators to be specified in declaration order; field bottom will be initialized after field right [-Wreorder-init-list]
libtool: warning: RNCSafeAreaViewState.o has no symbols
```

## Source-level fixes verified locally

1. Initialize `EdgeInsets` in declaration order: `top`, `right`, `bottom`, `left`.
2. Ensure `RNCSafeAreaViewState.cpp` emits a real external-linkage symbol even when platform guards compile out the implementation.

These changes remove the diagnostics without warning flags, suppression, or log filtering. I can prepare a focused patch if useful.