fix(display-list): make moveContents nonoptional

[Kyle-Ye]

Make ORBDisplayList.moveContents nonoptional in both the Objective-C header and the Swift fallback declaration. Update the DarwinPrivateFrameworks pin to the merged nullability correction.

The display list tests now use the nonoptional result and cover empty lists and repeated moves. All six focused compatibility tests passed against RenderBox on macOS; Swift import checks passed for macOS and iOS Simulator.

Dependency

• DarwinPrivateFrameworks#76 (merged)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (a5b6045) to head (df629d7).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
Sources/OpenRenderBox/Render/ORBDisplayList.swift	0.00%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main     #34   +/-   ##
=====================================
  Coverage   0.00%   0.00%           
=====================================
  Files         11      11           
  Lines        371     371           
=====================================
  Misses       371     371           

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