isExcludedPath function
Whether relativePath sits inside a directory that should never be
scanned (.dart_tool, .git, or build output).
Matches whole path segments, so .github/ or builders/ are not
mistaken for .git/ or build/.
Implementation
bool isExcludedPath(String relativePath) {
final segments = p.split(p.normalize(relativePath));
if (segments.isEmpty) return false;
return segments.contains('.dart_tool') ||
segments.contains('.git') ||
segments.first == 'build';
}