refactor(Node)!: make Node.root a required attribute

[susnux]

• resolves Should NodeData.root be a required property? #791

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.50%. Comparing base (f442781) to head (60fbb21).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1388      +/-   ##
==========================================
- Coverage   90.69%   90.50%   -0.19%     
==========================================
  Files          23       23              
  Lines         666      653      -13     
  Branches      181      175       -6     
==========================================
- Hits          604      591      -13     
  Misses         51       51              
  Partials       11       11              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.