Fix: flatten polyline materials and restrict Polyline.material types

[zgpky]

• Flattened PolylineArrowMaterial, PolylineDashMaterial, PolylineOutlineMaterial, and PolylineGlowMaterial
• Removed redundant nesting of material properties
• Restricted Polyline.material and Polyline.depthFailMaterial to accept only PolylineMaterial, str, or TimeIntervalCollection
• Updated tests accordingly

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.80%. Comparing base (d34662e) to head (a7795c4).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #64      +/-   ##
==========================================
- Coverage   99.80%   99.80%   -0.01%     
==========================================
  Files           9        9              
  Lines        1564     1550      -14     
==========================================
- Hits         1561     1547      -14     
  Misses          3        3              

☔ 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.

[Stoops-ML]

Thank you so much! Great work!

Looks like you need to apply ruff format and ruff check —fix to pass the quality test. Then you’re all good!

[zgpky]

I’ve applied ruff format and ruff check --fix as suggested.