isNestedSpmLayout function
Checks if a Package.swift uses the Flutter 3.41+ nested layout.
Implementation
bool isNestedSpmLayout(String packageSwiftPath) {
final file = File(packageSwiftPath);
if (!file.existsSync()) return false;
final content = file.readAsStringSync();
// Flutter 3.41+ nested layout uses Sources/ directory structure
return content.contains('Sources/') || content.contains('path: "Sources/');
}