555 open issues have no parent and no children — they sit outside the relationship graph #15441

Of 8,385 issues, 650 hierarchy links reach 645 leaves under 72 parents. 555 open issues have neither a parent nor children: they are invisible to every hierarchy view, roll up to no umbrella, and no progress bar counts them.

This is the largest gap the relationship adoption left, larger than the 19 empty umbrellas.

Acceptance criteria

• Every open issue either has a parent or is a deliberate root, recorded as such
• The count is reported after the sweep