removeYamlPath function

String removeYamlPath(String text, List<String> segments)

Edits text so the dotted segments path is REMOVED, keeping every unrelated line byte-identical:

• the leaf key line and its block body are deleted;
• an ancestor whose block becomes empty is deleted too (a removed last leaf under models.overrides.zai.glm drops the emptied glm: / zai: blocks up the chain);
• a missing path is a no-op.

Same line-scan rules as upsertYamlPath (the CRAP ratchet split those helpers out; this one shares them).

Implementation

String removeYamlPath(String text, List<String> segments) {
  if (segments.isEmpty) return text;
  final hadTrailingNewline = text.endsWith('\n');
  final lines = text.isEmpty
      ? <String>[]
      : (hadTrailingNewline ? text.substring(0, text.length - 1) : text).split(
          '\n',
        );
  final foundAt = <int>[];
  var cursor = 0;
  for (var depth = 0; depth < segments.length; depth++) {
    final found = _findKeyLine(lines, segments, depth, cursor);
    if (found < 0) return text; // absent path — nothing to remove
    foundAt.add(found);
    cursor = found + 1;
  }
  // Delete deepest-first: the leaf's block body, then emptied ancestors.
  for (var depth = segments.length - 1; depth >= 0; depth--) {
    final keyLine = foundAt[depth];
    final end = _blockEnd(lines, keyLine, depth);
    lines.removeRange(keyLine, end);
    // An emptied ancestor block: the parent key line now carries no body.
    if (depth > 0) {
      final parentLine = foundAt[depth - 1];
      if (_blockEnd(lines, parentLine, depth - 1) == parentLine + 1) {
        continue; // loop's next iteration removes the emptied parent
      }
      break;
    }
  }
  return _join(lines, hadTrailingNewline);
}