startTrace method
Starts a new trace for an ODBC operation.
The operationName should be descriptive (e.g., "odbc.query").
Returns ResultDart with trace on success
or TelemetryException on error.
Implementation
@override
Future<ResultDart<Trace, TelemetryException>> startTrace(
String operationName,
) async {
final traceId = _generateTraceId();
final now = DateTime.now().toUtc();
final trace = Trace(
traceId: traceId,
name: operationName,
startTime: now,
attributes: {},
);
_activeTraces[traceId] = trace;
return Success(trace);
}