truncateToTokens function
Truncate content to roughly maxTokens, keeping the head.
Implementation
String truncateToTokens(String content, int maxTokens) {
if (roughTokenCountEstimation(content) <= maxTokens) return content;
final charBudget = maxTokens * 4 - _skillTruncationMarker.length;
return content.substring(0, min(charBudget, content.length)) +
_skillTruncationMarker;
}