isStructuredProtocolMessage function
Checks if a message text is a structured protocol message.
Implementation
bool isStructuredProtocolMessage(String messageText) {
try {
final parsed = jsonDecode(messageText);
if (parsed is Map<String, dynamic> && parsed.containsKey('type')) {
return _structuredProtocolTypes.contains(parsed['type']);
}
} catch (_) {}
return false;
}