Some -of-type fixes

[wRAR]

1. ns|* with -of-type pseudo-classes counts the namespace, not the type
2. The root element never matches :only-child/:only-of-type

Found and fixed by an LLM, all test cases validated manually.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.61%. Comparing base (743c6e5) to head (00dbf6a).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #170   +/-   ##
=======================================
  Coverage   96.61%   96.61%           
=======================================
  Files           3        3           
  Lines         885      886    +1     
  Branches      136      132    -4     
=======================================
+ Hits          855      856    +1     
  Misses         14       14           
  Partials       16       16           

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