Fix async renderer inherited view update crash

[Kyle-Ye]

Agent Summary

This PR fixes an async renderer crash when inherited view updates are processed during transition rendering, and adds a focused Example view for manual verification.

Changes included:

• Capture the display list platform before entering the async view-cache update callback so the callback does not read through the mutating cache state.
• Rename the async rendering example file and add a transition-focused example that documents the affected rendering path.
• Implement the AppKit NSHostingView._renderAsyncForTest(interval:) path so macOS test hosts can drive async rendering consistently.

Validation:

• Not run locally; OpenSwiftUI build/test commands are intentionally skipped unless requested because they are slow.

[augmentcode]

🤖 Augment PR Summary

Summary: Fixes a crash in the async renderer when inherited-view updates occur during transition rendering, and adds manual examples/tests to exercise that path.

Changes:

• Captures the display-list platform before entering the async inherited-layer update callback to avoid reading through mutating cache state.
• Replaces/renames the async rendering example and adds a transition-focused example that reproduces the previously crashing rendering path.
• Implements NSHostingView._renderAsyncForTest(interval:) on AppKit so macOS test hosts can drive async rendering deterministically.

Technical Notes: The core fix is a closure-capture change that avoids Swift exclusivity violations during inherited layer updates.

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[augmentcode]

Review completed. 1 suggestion posted.

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[augmentcode]

repeat { ... } while !propertiesNeedingUpdate.isEmpty can potentially spin forever if renderAsync(targetTimestamp:) returns nil while propertiesNeedingUpdate stays non-empty (e.g., a stuck update flag), which would hang tests. Consider ensuring the loop has an exit condition when didRender is false (and that canAdvanceTimeAutomatically is always restored).

Severity: medium

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 17 lines in your changes missing coverage. Please review.
✅ Project coverage is 26.28%. Comparing base (cf9a0d4) to head (725453e).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ntegration/Hosting/AppKit/View/NSHostingView.swift	0.00%	16 Missing ⚠️
...re/Render/DisplayList/DisplayListViewUpdater.swift	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #904   +/-   ##
=======================================
  Coverage   26.28%   26.28%           
=======================================
  Files         710      710           
  Lines       49705    49719   +14     
=======================================
+ Hits        13063    13070    +7     
- Misses      36642    36649    +7     

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