detect method
Detects the capability, or returns null if not present.
Implementation
@override
Future<Capability?> detect() async {
final result = await runProbe('clinfo', ['--list']);
if (result == null || result.exitCode != 0) return null;
final out = (result.stdout as String).trim();
if (out.isEmpty || out.toLowerCase().contains('0 platforms')) return null;
return const Capability(kind: CapabilityKind.opencl, name: 'opencl');
}